There are already some pretty great responses, but I'll weigh in as well>Lite not enough, Basic too heavy
Lite keeps the scope limited to semi-realistic fairly able-bodied humans. Basic is effectively a reference book, and if you consider Lite the core of the game (which I and several others do), then Basic is almost entirely optional. If you treat it as optional and make a snap ruling because you can't remember, the only people who will be upset are rules lawyers. The kinds of contests and such available, if you come to appreciate them, can do a lot of work. (I once couldn't remember feinting rules, but because I had come to appreciate the design of GURPS, I basically made a ruling which was an almost exact match of the written rules.)>genre book
Not by necessity, but it is my opinion that the genre books are a great boon, usually being well-written, well-though out tools. If you have questions about which splats would help make the game run better for the kind of campaign you're trying to run, anons will usually be happy to answer. For instance, my goto answer for "how do Fallout?" is "Lite with After the End + some cinematic rules, depending on what you value about Fallout">Load on the GM
The load is more obvious because there are more tools available in the core books; you can ignore them and fly by the seat of your pants if you want. This can be a difficult but rewarding experience, and I recommend coming to love the text of "The Lazy Dungeon Master".>how to remember disadvantages?
Literally write yourself a cheat-sheet of the PCs with short descriptions of their high concept and traits. "Vale: smooth talking socializer. lecherous (6), gambler (9), very handsome">central mechanic for everything!
I mean, yeah, that's been the guiding philosophy of many games for a few years. 3d6 < skill is a pretty simple and satisfying mechanic, especially when you abuse the fuck out of quick contests, or abuse "narrative" game philosophy.