Playing as a Sentinel with 16 INT, you could keep all 6 of your class skills maxed out throughout the game. I wouldn't recommebd that, though. I would take Demolitions and Repair as class skills with my first two feats, then work from there.
I like to keep Persuade and Security maxed out - Persuade is the one skill your party members can't handle for you, and late in the game you're apt to find locks with crazy DCs. Awareness (mines), Computer Use (upgrading T3), Demolitions (mines again), and Repair (workbench) all go to 20 as fast as I can get them there. Treat Injury gets the leftovers (it's not a priority if you take the Force Heal powers - except for certain quests, but they don't seem to need a very high skill to pass), and Stealth gets one point - at most - through the entire game (first, it's not that useful, and second, I always seem to end up with tons of +STEALTH items).
But you can do it any way you like. It's not as if the game is extremely difficult... when/if you can get it to run, anyway.