In options you can fix all that. Most of SSC is customizable. In song options you can turn off mines, the judge/life default is set easier when you install it originally (Like 3/3 or something, you can change it back).
While SSC is made to fix virtually everything in 4 and 3.9, its still only at RC2, and only just got off the ground. It sucks that you can't get into it, most people on KBO think its fantastic (me included). But to each their own. At least you tried it. And its to bad about the timing thing. I know there are people around there who can help you out if you have any questions about it.
As for theories, they've existed since a0.com, and probably won't go away anytime soon. The only "theories" that seem to be around these days are x-mod/mine/layering and some stuff in Solo. Although people might mention that "those 32nds are supposed to be 24ths" they aren't gonna be dicks about it. Most people have decided that if you want to be a douche and talk about theories and why your chart is better example of said theories, they just ignore you and piss off.
While it is pretty old school thinking to say "Why bother about the technicality, I just want to play for fun. Gimmie the old days" etc., the general consensus is that if the game is evolving, so should the player base and the files. Soon there will be such things as "lifts" where you need to have your finger off the key at a certain point, and even roll theory. A lot of people have moved on from the "old days" and are quite happy with the way things are going.
I play spread, so I can handle layering. I'm getting good enough that most triples and quads aren't really an issue, unless someone just piles on the bullshit (also triple jacks/quad jacks are retarded). And I do definitely see merit in technical simfile design. I've always felt that the simfile should follow the timing and possibly laying of the original song as closely as possible, etc. (None of that "i made up the rhythm" crap that you see in so many shitty first time files, or in crappy official charts to make things easier).
I have never been a fan of mines, and rolls, and the lift thing just sounds retarded (even if it is a logical extension of the game). If I wanted something to penalize me for pressing at the wrong time, I'd go play djmax.
Part of the reason I kinda miss the older simfile generation is that I'm missing so many of the ones I used to have, and I don't even remember all of them any more. I used to have a huge collection (like, almost 2500 songs), but it got wiped out a while back. I'm up to like, 1k now, but I'm missing a lot of the older tracks that weren't in packs, and such. I used to have like full collections of the guys on a0 and such. I used to have a (nearly) full HST collection, among other things. and I'm finding that although I can play many of the newer tracks, because I'm still not all that good, I don't find many of them to be all that fun.
As for SSC, I'd really like to make it my main. I definitely think it's a huge improvement over 3.9, but I'll need to sort out all of my issues, and that's gonna take a while. Maybe I just need to play it more often (whenever I would switch from SM to o2jam, I used to get the same sort of feeling like the timing was fucked up, due to the different timing system).