There were several plotpoints about how there was NOT surplus of antimatter (or whatever propellant they used). And in case of "blowing up" they could use thos

There were several plotpoints about how there was NOT surplus of antimatter (or whatever propellant they used). And in case of "blowing up" they could use those am engines as LAS (they apparently had enough thrust), so what risk are you speaking about? Seriously, bitching about science stuff in Interstellar, very large but actually very well crafted scifi is kind of dumb. It's big enough that you find SOME mistakes, but most of the time you'll be wrong (or blaming them for not explaining every detail), and it has pretty correct science overall. Just hating for sake of hating.