Did you create a midi track, and then throw an external instrument rack on it? Then you just need to select your drum machines midi port, and the audio channel it is coming in on. Screenshots of your setup would help.
LSDJ should crash very rarely actually on a unmodded, clean slot. Have you an unmodded dmg to test it on to compare the behavior of your songs/cart?
Ive found that some of my store bought mods are very picky when in lower power situations, whats the MAH draw of some of the common backlights versus the stock LED that comes with a dmg?
I think piggytracker would work really well in the touch interface if you replaced the screenmap and commands with touch menus. Im not a fan of how sunvox does this on touch devices though, so maybe its harder than it first appears.