BB Banter took a look at whether or not the BP has been overused, judge for yourself: http://www.bluebirdbanter.com/2014/4/21/5636674/is-the-bullpen-overworked
Now, yes, your point stands, in that if the starters continue to not go deep into games, it could become a problem. Gibby could've given Morrow a longer leash on Sunday, for example, but he took him out after a leadoff single in the 6th. He also let Loup throw 29 pitches and ended up using Cecil down by 2.
As for Gibby's BP management, we all like the way he handles it, but there have been some iffy decisions for me so far this season.
Let's hope it all works out!