i have read these forums for many years and almost once a week there is a post that says something like dont look at overall ratings they dont matter  and as i do belive the cores are way more important than overall ratings i do belive they matter somewhat  so the real question is what ratings dont matter and how high in each division does a rating need to be to be profiecent . im gonna start with durability i have only ever lost 3 players ever for more then a day to day so it would seem by most that this is a useless catagory but you tell that to a guy that loss a player in the nt or someone that lossa few players in a season so what number does durability need to be so your player doesnt get injured i dont know if there is a answer for this witch makes durabilty the most confusing catagory ever but if someone has a clue on this i would love to know. the next is work ethic this is pretty straight forward as it does matter to improve your players and while recruiting but doesnt matter on the floor so no need to go on with this. stamina i would belive matters to some teams and offenses and defenses  more then others i think if you have a short bench a couple bad players and walk ons it means much more then a team with 10 to 12 decent players and it should matter more in a press then a zone . passing this is a core rating and very important for guards but with big men this is not important but since motion and flex involves alot of passing shouldnt this be important  as well i would think that a 40 passing c is better then a one especially when i read the pbp and my center or forward passes it out of bounds every day the same thing can be said about ball handling when your center misses a pass. perimeter is next  also very important in gaurds but isnt it nice to have a decent perimeter bigman that can throw up a 3 from time to time to make your team a gamplanning nightmare for opposing coaches the same thing can be said about lowpost  next is blocking this is where it gets fun because i have no clue about blocking  i have noticed that ath weighs more into the blocking then the actual catagory i guess if its higher than a 70 in d3 or 80 in d2 it does matter but other then that i dont get it at all. next is rebounding this is very important in bigs but not that important in guards but if your bigs are not great rebounders having a guard that can pick up a board is important or if the other team has weak rebounders this can help get a advantage im not gonna get into ath def and speed because these are important in all players   so in short what ratings dont matter and how high should the rating be to be decent at it  also p.s i didnt get into how bh goes into a decent perimeter and ath and speed goes into almost everything being better but realy how doesnt overall matter at all

I think you're correct about DUR and WE.  Unless they changed it recently, good durability reduces the severity of an injury.
I like my stamina to be at least 70, preferrable 80+.
I think blocking helps with DEF.
I ignore PER in my big men but many coaches disagree.
I like my REB to be at least 70 for D2,  60 for D3.

I used to not take anyone with a Durability below 30 but it seems now that it really doesn't matter.
WE plus starting HS GPA is a strong indicator of how fast a player will learn IQ. WE also impacts player skill improvement (along with playing time/starts). I never take anyone below 25 but some coaches say don't go below 30 for WE.
I agree with alblack56 on stamina. The lower the stamina of your starters, the more time your backups will get. If your backups are solid that may not be an issue but in some cases there may be a big dropoff in quality. It is definitely more important in the Press.
BH/Pass is obviously more important for guards than bigs. For bigs, this is an area I am willing to compromise on for the sake of other cores. I also believe BH helps in Per but I cannot explain why.
I ignore Per in bigs except in Flex.
I think SB is somewhat important in Zone and nice to have elsewhere.
If I have guards grabbing more than 2-3 boards per game then something is way out of balance.

Just a suggestion but next time you type out a long post put some spaces in there so people can actually read it.

As for core ratings by division I would say for a starter at D3 minimum 60s for, D2 70s (although there are some ratings like rebounding for big men or BH/passing for PG that I would want in the 80s), and D1 as high as you can get.

Just have the impression lately that somewhat unannounced, the importance of WE in your players' development has been tweaked.  Seems to mean even more in the development of your guys during the season, and during the summer than in did a few seasons back.  While I would sometimes take a guy with a WE in the upper 20's, now you have to think twice about anyone under 40, even though WE is just another attribute that can be improved--so long as you give the guy some PT.  ST and DU, unless the guy has red numbers, are fairly easy to build up with conditioning.  

Blocking effects an opponents FG%, so while the player may not actually block a shot they can "get a hand in the face" of the shooter to effect the shot. 

If you are looking to develop your team, then WE is important. If your trying to figure out why one team beat another team, then WE doesn't matter.

I haven't seen a correlation between the likelihood of an injury and DU. The does seem to be a correlation between severity of an injury and DU. Since injuries are rare, there severity of an injury is not much of a factor.

The rest of this focuses on guards:

I'm not sure how much passing matters anymore. It makes a difference in assist allocation, but it doesn't seem to have as big of an impact on turnovers as BH. At DIII, an 80/40 BH/P guard is better than a 60/60 BH/P guard, IMO.

There are a lot of really good coaches who are big on DE. I think DE is important, but it only needs to be good, not great. At DIII, if my players are above 40, then I'm happy. More is better, of course, but if I had 120 points to allocate between DE and PE, I would go 40/80 DE/PE. I would prefer that over 50/70 DE/PE and over 30/90 DE/PE.

ATH and SPD are both really important. If I could choose among a pool of guards with 120 ATH+SPD points, I am fairly ambivalent about the allocation as long as the ATH is not below 30 and the SPD is not below 45 or so. So, I am okay with a range of 30/90 ATH/SPD through 75/45 ATH/SPD.

I couldn't make it all the way through your post, but, skimming every few words.  I'll explain the little that I know.

Durability - does not seem to affect the likelihood of injury, but only the severity and the duration of recovery.   However, should you take a bunch of recruits with DUR<30, then you will eventually lose one for around 10-15 games...eventually.  Otherwise, this does not show up in the box score.

Work Ethic - does not show up in the box score.  As Allen Iverson said, "we talkin' 'bout practice!"  This affects only how fast the player will improve in ratings and, along with HSGPA, how fast IQ will improve.  

Stamina - only shows up in the box score when played too many minutes for that particular system and stamina rating.   When it does, then it has a big effect in efficiency & fouls given.  If you have enough depth, then a gang of high-skill low-stamina players can perform very well.

So, many coaches compare recruits' potential performance without regard to the 3 categories above.  Clearly, stamina works its way back into choices on the depth chart and tempo.  But the more complicated part of your question is about the impact of non-core categories on a player's performance.  The quick & dirty is this:  

1. ATH & SPD matter greatly at every position;
2. LP & PER affect scoring efficiency at every position;
3. BH & PA affect turnover rates at all positions; and 
4. At D2 you can't have everything.

I would say the cores for guards are SPD, DEF, PER, BH & P.  While frontcourt cores are ATH, REB, DEF, SB & LP.  If you sum up the cores, then you get a 5-500 scale.  In my opinion, this scale is what matters, not even any individual "core" category.   

Wrapping it up, why the hell would you even want your PG down low fighting for rebounds and trying to block shots or your C dribbling the ball, spotting up for 3's and entering the ball to the post?  Sure, it's nice if their able to do so, but the sim will probably not have them in position for those categories to matter very often either way.

I counted 7 sentences in that novel.  Someone needs to quit playing hoops dynasty during English class.