That first sentence from fsbarren's post above is exactly why I banned acquisitions once the playoffs start, only making exceptions for contenders who have players legitimately go on the DL during the playoffs.
I also think 60 is a bit low for moves (even though there are theoretically only 65 allowed in my league) for the reasons he gave. I prefer leagues with unlimited transactions for non-streaming purposes, but there's no way to differentiate unless you maybe institute a longer waiver period. I suppose you could make a rule that all players acquired have to stay on a team's roster for maybe 3 days or something.
One radical solution that a commish has in a league I'm in is to only have one SP slot. I'm not sure I'd go that far, but allowing for fewer SP slots and watching for people who try to start pitchers with RP eligibility is also an option.
A 'max starts per week' won't work on ESPN because...say your max is 10. It's really "nine plus however many starts one can fit in on Sunday". I've used that loophole, and people have used it against me - often at the same time.
Anyway, just a bunch of ideas.