possible problems
Exalted means absolute, no compromise, toe the line, goody two shoes. Remember all those threads about what LG characters and Paladins might get away with? You can't even get away with that stuff. When in doubt, always assume the stricter interpretation applies. If you screw up even once, you can permanently lose all your exalted feat benefits, including those of vow of poverty.
You may run out of "useful" bonus exalted feats, especially if your ability scores are not high enough for some of them. This may lead to the Vow of Peace being your only option, which could radically change the game for the rest of your party.
You still take a share of the treasure, but it must get donated to a charity. Other player characters do not count as a charity. Note, donating this much to a single charity can seriously mess up the econony of the area.
Since you are limited to your special monk and VoP powers (plus racial abilities, if any), this limits your tactical options. Other player characters can more greatly tailor their abilities to a situation by getting the appropriate magic items.
For the first four levels, you still have to eat and drink, yet can carry no more than 1 day's rations at a time. This can get tricky. You might need ranks in survival.