So the issue is timing. I used to be able to lay all the Trip Mines I felt like, then Time Bomb and immediately use Fold Space. The mobs would materialize on top of the Time Bomb exactly as it detonated AND the Trip Mines went off too, killing every living thing before it could do me much harm.
Yes, it was cumbersome to set up, and not a fast way of blasting through crowds, but it was safe and extremely hilarious.
Now I have yet to figure out how to do that timing correctly, so that Time Bomb/Remote Bomb and the Trip Mines are effectively simultaneous.