I'll start with noone is trying to argue with you (and since this is text, interpret my tone as a non snippy one). People in this thread so far just seem to be asking what in fact you are looking for. Don't come off so negatively if you disagree or don't get the answer you're looking for. You appear to have given up before you've even gotten started. If you disagree with the answer, ignore or discuss. If its not the answer you wanted or its not clear, ask them to clarify, be more specific in your question, or reword the question.
Back on topic:
I have to agree with mully. you have C prestige which is pretty low. More than likely the other guys have higher prestige. It is not easy to pull a recruit or even get decent drop downs with a C prestige.
Also, there are just some guys you can't pull down and/or won't drop down (this is also usually related to prestige. If your initial message to the guy said something like there is no chance, then you need to move on). Also, just because someone said the usual amount is 10 ST's, does not mean it will be 10 for every recruit, especially at a C prestige. In many cases, it might be 20 or 30 (usually at the higher levels). Other cases it might be 5. No number of ST's will change the responses you get until you hit the magic number that he has officially removed the backup label off of you. Highly rated guys are going to be harder to pull down and more competition means he has more choices, so he doesn't need to rush into a decision to drop down for you which is why more competition might make it harder. Like you said, it is a guessing game, but not completely. If you pay attention to things like how many open scholarships does this other coach have open, how many players are considering him, how many battles is he in, is he in a good conference, WOTS, etc. These kinds of things give you an idea of how much the other guy is working with and maybe how much he might have spent. You never know how much a guy has put into one player unless he tells you (which should not be shared until after recruiting). Some guys might have 4 open scholarships and use the entire total to get 1 or 2 players and take some walkons.
Recruiting in real life is a guessing game. A recruit is not officially committed anywhere until he signs the papers. Add to that, this is not real life, there's only so much that you can put into computer programming. Pay attention to the WOTS in the players profile (if you did FSS).
As far as specific messages, pretty much you are backup until you are not a backup. If anywhere in the message (coach call, ST, phone call, etc) it says he is looking at his better options or that you are a backup, then you are. If it says anything different (with exception to the obvious he just doesn't like you or stop calling him), more than likely you are not a backup and you can recruit freely with HV or CV etc. If it says something to the effect of hes not sold or he has to visit another school or someone else beat us to him you are not a backup, but you are not leading or even being considered yet. As long as it does not specifically tell you he is looking at better options or that you are a backup.
If you have a message specifically that you are not sure about, put it in the thread and someone can tell you what it means. I'm sure someone probably has a link to another thread that specifically tells you what each message means.