[WEIRDWOLF]

I probably won't join any leagues because of my location, but I might be into some tournaments.

Michigan has LOTS of leagues and players from the U.P. on down. Where are you at?

First off, figures...
There's the traditional figures that come with a new game.
I found a couple of other sites that sell figures as well. 4buzzball.com, inthezone and footballfigure.net. Are there any other sites?
5-13 on this forum also makes some nice custom production figures as well as Dewayne Jennings (egridiron) from Electric Gridiron. There are probably others but I'm blanking on them right now. Sorry to those I am not thinking of.

Bases...
From what I can tell from reading, there are
"rookie" bases. These pretty much just go straight ahead. What would you use these for?
They actually go many directions depending on how they are tweaked but they are the basic starter base. They can be used on just about any position but are not often used as linemen.

Then there are TTC. This makes players go in any direction by turning the dial. Is there a difference between these and ITZ dials that I see mentioned?
Yes ITZ dials have the ability to move sideways.

I found another site (Miggle's, I think) where they have...
speed bases,
pro-line bases
...and what's with all the different colors?
These are bases that were created for the annual Miggle tourney. Each year they have a new color.

What are the differences with these compared to the ones I listed above? I'll let someone else tackle this question. There could be (should be) a book on this.

Looping linebackers...I think I understand what they do...how do you create them. A specific figure. What base do you use and how do you tweak it?
Better do a search for loopers. Another huge question.

General rules question...This may be different depending on the league.
Do QBs have to be on non-mobile bases?
No

With any player, can bases be changed in the course of the game? Depends on the league you play with but usually you will want to switch out a player/base combo rather than switch bases. Bases perform differently with different figures and it can be hard to keep track of what base you have on which man.

Speaking of which...I saw that someone mentioned something about bases that allow players to move laterally. Who are these available from as I did not see these on any other sites.
Those are ITZ bases. PM Mark Klingbeil (forum name "mklingbeil") for those. I believe Geno (Geno H) also sells some tweaked.

Also, do the TTC bases allow linemen to pull? Yes, too a degree. There are others on here who can detail this better. Read some of Reg Rutledges posts in his Shootout Rules section.