For a second I thought this thread would be about the movie "Marathon Man" from the thread title.
No you should be okay, you have to rtemember that even playing pretty loud your not even coming close to using anything nearly as close as 350 watts. Your more in danger by underpowering the speakers than havinga ll the watts in the world. Your speakers can handle alot of power hence why your not having any issue playing so loud. Your fine.