One of my players is making a sorcerer for my upcoming Skull & Shackles game, and is asking if he could apply Improved Bull Rush (and presumably, the rest of that feat tree) to spells like Hydraulic Push, Hydraulic Torrent, and Interposing Hand.
Is this against the rules? Is it just plain a bad idea? I'm not a huge fan of the idea, but I don't want to just say 'no' because of that.
I would say, if he is willing to pay the pre-requisites and blow two or more feats for a thematic idea, by all means it should work.
A strict reading of the Hydraulic Torrent spell "...Against creatures and moveable objects this stream acts as a bull rush. You can bull rush creatures of any size, not just those one size larger than your own. Make a combat maneuver check and apply its results to each creature within the area...."
It should work.
If you are having trouble visualizing it, consider that his specialized training in knocking people around gives him insight on where to point the magical firehose to knock someone off a ship.