1. How do you get credits for the Torishop?
2. Once you buy something in the Torishop can you keep it forever?
3. What do mods do?

1.
a. Playing/winning in specific servers
b. Selling items, textures, and others
2. You can keep it forever unless you sell it.
3. They let you play in various environments like houses, cars, and lots more.

1. There are many, many ways.

a) By playing the game.

Normally win your matches
(10 TC in each official server, except in Ultimate servers, where you gain 15 TC each win)

Purchase a booster to get more TC each win
(Pay by Mobile phone or PayPal)

Game Events
(Tournaments, replay events etc...)

Betting

Dueling
(In fact, a really bad way, because you can be easily tricked and you won't be paid...)

Bounty Hunting
(Alternatively...)

b) By making art.

Design Events

Requests and shop

Projects

c) By doing... Other stuff

Marketing

Random events
(They mostly are in Game Events forum... Events like the Great "500" Event or Retro games comp... Pretty much random contests, you get the idea?)

Giving out GOOD ideas for Projects

d) Purchase dem!

2. Yes.

3. If you mean modifications... Press Ctrl + M in game and select some mods to see what they do.
If you mean moderators... They keep the forums clean from posts, threads and people who break the rules.

then how much do you get in light/middle/hevy weight boxing servers

Thanks guys. One more question. Can you delete replays?

Yes.

If you mean deleting from Toribash, then just delete them from your replay folder (not in game) like any normal file...

If you mean in the forums, go to your post -> Edit -> scroll down a bit -> click remove next to the attachment replays.

5-15 TC I think.

Nother question...I multibuyed two relaxes in the Torishop. They didn't appear in my inventory. Will they show up or should I buy again?

I'm not completely sure, but I had to put this way of making money too:
You can make your own .on.toribash link and get 30tc for each view of another person. Also, you get 100 if that person joins Toribash (but I'm not sure how that works out)

See this link for how to get one.