*bamf*
Sorry for the long delay, real life trudged on my turf and I had to clash with it.
The Marian reforms happen once there's an Imperial Palace in Italy, that city can't be Rome however and Sicily doesn't count. This was tied to dates in the previous patches(109 BC and Imperial Palace), but in the most recent patches you just need an Imperial Palace, I've seen the reforms as early as 265 BC. I almost never play as Rome though. I don't think I've even started a Rome game since Vanilla RTR Scipii campaign a year back.
As for attacking the Senate or civil war, once the meter for your standing amongst the populae tops your standing on the senate, the senate begin giving hard missions, on which failure usually results in either: a) your faction getting expelled or b) your faction leader having to do seppuku. The best way to get the vox populi on your side is to conquer like heck, this means that the Civil War wills tart pretty much eventually and unavoidably. I mean, the point of the game is to conquer like provinces were cherry hotcakes, right?
About the 1.2 version being baaad and RTR, it's now possible to install a 1.5 port for RTR, called RTR Platinum. It's a nifty mod and very well balanced, some great additional ecomonic mods and four turn per year are available for it too.
I'd like to ramble on, but the truth of the thing is that I'm pretty burned on RTW after
EB, Blue Lotus, Terra Expugnandae and various versions RTR Platinum.