It seems most people use the WW to fill occasional holes, from injuries or a failed plan, but how often do teams max out on yearly claims? Is it frowned upon to make a lot of claims?

I realize the majority of players are marginal at best, but how big of a role does it play in new owners re-building/re-establishing "dogged" teams?

1-I can't recall anyone maxing out. If it hapens, it's infrequent. Or not mentioned. With a 2/day limit, you'd have to make a concerted effort to burn through 50 claims.
2-The worse the ML team the more WW is likely to be helpful. After the initial FA frenzy, you can usually find a cheap alternative to second-tier FA for a lot less on the WW, though usually not quite as good. It also depends on what holes you have. If you're looking for a backup COF/PH, or a bullpen filler, you'll find one. If you need a SS or leadoff hitter, not so likely.