i had the same problem in my basketball league a few years ago, and all the members were friends and seasoned fantasy players.
i actually was the person making the trades day in and day out, just to cover open roster positions. at the time, it made sense b/c i was able to get people in to play and ultimately won weeks.
but in retrospect, i dont think it was necessarily 'shady', but i think it may have dinged my reputation as a fantasy owner in that i only held players for a short time. sometimes for even just one day. so what happened there was that a lot of players didn't want to trade with me. futhermore, some of the players would be in 'waive' status, so there was always a player clog since there was a 2-day wait period.
also, it could HURT your team in that some players that are hot one day can be cold another, so you never let the player shine on a 3, 7 or even 10 day average (like Reggie Sanders).
sure, you can argue, 'well, commish didn't set a limit and i have every right to do so'. this is true. but i think there are intangible disadvantages to this strategy, as so mentioned above.
personally, i've made about 12 wire transactions so far. mwb743s mentioned his leader make 65. i'd be a little concerned with that many trades as he's obviously filling voids and not trying to upgrade his team. but again, this is subjective and MAYBE he IS upgrading his team and very arguable, since it's 'within league rules'.