As the one chosen by XiaNaiX to be a moderator when he took his "leave", I am proud to help you out.
First off, let me give some answers to your goals/questions.
1- Possible with the tools found at Gitbrew.org(gititbit) and Rebug.me, both links can be found in my sig
2- TB lets you play some of the newer games, but not all of them. Also, you can not use the latest updates for the games sometimes, as if causes an error I assume.
3- Easy, you can do that with the mmCM/multiMAN tool, or even Rogero Manager
4- This can be done with the use of a hardware flasher, ProgSkeet(.com) and E3 Flasher(e3-tech.net)
Now as for CFW options, Kmeaw is the standard. Rogero has one that should be used for downgrading with ProgSkeet and E3 Flasher. Other than that, you are getting into MFW territory, things like Ultimate CFW and Newbie Friendly Ware. TB actually comes with it's own CFW. As for best backup support, it seems Corba-USB can handle any backup you throw at it. Cobra makes their own CFW too, but their is also an NFW(MFW) version of it as well.
PS, I do not know who killed your saturn sigs, but I got a good guess
EDIT - Be sure to check out the
Contest! link, it has a great tutorial from Shaitan about easily swapping between CFWs, so you can have it set up Kmeaw, TB, Cobra, Rebug, and OtherOS++ for instance.
Also, I hope your PS3 is not higher than 3.55, or you will need to start of with a hardware flasher right away. The scene right now is basically 3.41-3.55. 4.10 you can access PSN but no CFW; that is to say, not until you downgrade.