any way to remap keys for only one app?
Keyboard Maestro might be your thing. Make a new command group which only applies to the application in question, then for each key you want to remap, make a new command with a hotkey trigger set to the real key and an "Insert Text" action set to what you want the key to be.

The only shortcoming I've found so far is that it can't handle the in-built volume control keys on an Apple keyboard. It can detect them &amp; act upon the event, but it can't suppress the volume change. In fairness, nothing else can either. Most programs I tried can't even detect it. Keyboard Maestro is the king of the pile.