First, I most recently added MCaleb's Decompose Corpse, and a few others that aren't currently active since I started being more cautious. Just this morning I tried loading the mods in sections to see which worked and which didn't, and everything works alright unless SiC is active... but turning other things off isn't working anymore.
Second, I used OBMM to sort the load order.
Third, interesting, I tried recently to find the best modern versions of those, could you tell me which ones are the best upgrades?
http://tesivpositive.animolious.com/?page=boss is an automatic load ordering utility, in OBMM you'll have to do it manually. For the basics, read the website where I linked you to first on posting your load order - it has all http://tesivpositive.animolious.com/?page=tuning_oblivionnswered in one place.
Enhanced Hotkeys is a really new and improved hotkey mod (released last month), and is the most stable and bug-free. Search on TESNexus.
I think Animated Windows Lighting System (AWLS) (or is it Real Lights?) is a replacement for Illumination Within. I'll let some one more knowledgeable chime in on this. EDIT: I am right, see http://tesivpositive.animolious.com/?page=popular_outdated_mods.
Same thing with Beautiful People, I've seen others refer to improved race facial mods, but as I don't use those, I don't know... I use Race Balancing Project myself that has a beautification module, and younger hotter NPCs women. RBP has more features than just beautifying people, so I don't think that's an exact replacement. Again, someone more in the know should respond to this...
Regards to SiC, I've never used it (or heard of it).
Regarding the crashing issue, can you revert to the earlier save when crashing was not an issue. Something might have crept in your savegame that is causing all the CTDs. It could be a corrupted spawn issue (if that is the case, crashes will consistently happen in one area. Try to do something somewhere else for you respawn period time (default 3 days), and then return to the area to see if it still persists).
Also read the http://tesivpositive.animolious.com/?page=troubleshootingof the website.