I was thinking about purchasing this game (Gothic 2), however I am currently without a USB mouse to attach to my laptop. Is the mouse used alot in this game ( like looking around in an FPS or clicking it to attack) Also, would I be able to use a gamepad with the game? (I use a ps3 controller and downloaded software that allows me to use it)

Yes, mouse is used a lot.
You could play keyboard only if you want..there's a config for it.
Alternately Xpadder will let you map keys to your controller -- there's no native controller support. There are free (old) versions available if you don't wish to pay.

Note that Xpadder isn't specifically needed--any program that allows you to assign keyboard keys to button presses will work fine, and if the program you have already does this you're good to go.
Also be sure to go into the Gothic II control settings and turn off the Gothic 1 control scheme. This will simplify the controls a bit by not having to use the unusual toggle controls used by the first game.

This may be a surprise for some people, but mouse is not necessary at all. I play Gothic 1 and 2 using keyboard only. The reason is that mouse look in these games feels a little strange and not comfortable. Originally (before Gothic 1 release) there was no mouse support, and it was added last minute, because people writing previews were complaining. As noted before, the game has no native gamepad support, but you can use Xpadder or some similar program to solve this. Or just use keyboard only.

Would you mind telling how one uses only a keyboard to control? is it comfortable? I don't want to drop $10 dollars on a game and never play again because I can't use the control scheme,

The keys are customisable, so you can choose whatever scheme you are comfortable with. I never had a problem with controls (after adjusting them to what I found comfortable), but many people did, so I cannot guarantee that you will like it. What I use is:
Numpad 5, 8 - walk back / forward
Numpad 4, 6 - turn left / right
Numpad 7, 9 - sidestep left / right
Ctrl - action, Alt - jump, Shift - walk, Z - sneaking (toggle button)
Numpad 1, 2, 3 - character stats, inventory, quest journal
Spacebar - draw weapon (toggle button)
I also use Gothic 1 control scheme (something most people avoid, but I played Gothic 1 first and got used to it) - this means that combat controls work like this:
(With weapon drawn)
Action + forward / left / right / backward (Ctrl + Num8 / Num4 / Num6 / Num5) - attack forward, attack left, attack right, block
Num5 - jump back (essential evading move)
Ctrl while running - overhead swing (rather useless)
Personally I never had problems with controls, but I was playing Wolfenstein 3D and Doom back in the old days using keyboard only, so it may be just me being used to this control method.
I think the only tricky part may be the combat - using action modifier depending on whether you want to move or attack.
If you are not sure if you will like the controls, then I suggest trying out the demo. The link can be found in this thread:
http://www.gog.com/en/forum/general/demo_links_for_current_gog_games
And another thing - if you decide to buy the game, then do not install Night of the Raven add-on on your first play-through. The difficulty may prove game-killing for
beginners.