Glad to see you back and welcome. RMC is the replacement for your RM2. However many of us have found that while RMC is great (cleaned up, organized better, looks nicer), RMC isn't an absolute necessity. That said, Combat Companion is pretty sweet.
RMU is still a work in progress, and as of the last Directors Briefing (
http://www.ironcrown.com/ICEforums/index.php?topic=19481.0) it's in the editorial queue. Slower than we all want, but we want it done right, rather than fast.
As far as settings go, Mr. Amthor has been tearing it up lately, and has just released a new Shadow World Sourcebook Haalkitaine (available on RPG now as PDF, soon as hard copy (or I've seen posted)). He's also recently released a new SW module as PWYW (again on DriveThruRPG).
Rolemaster certainly isn't dead, just laying low. Fair bit of activity if you know where to look for it, and I was pleasantly surprised to have recently seen Fantasy Grounds VTT activity. There are a couple of YouTube channels where RM groups post their VTT activity. A few other resources: the Rolemaster Blog; it has some very good RM / d100 discussions there and also the Facebook group. RM Reddit group was banned for some reason (still trying to figure that one out), but I think it's being worked on.