Replying to Few t2i and accessories questions

1. When people say the t2i can only do 12 min of recording, does that mean the battery only lasts up to 12 min? or the memory card can only hold 12min?

2.http://www.amazon.com/Dolica-AX620B100-62-Inch-Proline-Tripod/dp/B001D60LG8/ref=sr_1_4?s=photo&ie=UTF8&qid=1297195794&sr=1-4 I like everything about this tripod ( including the price) except i dont like how it doesnt have a handle to turn the camera and would seem a bit hard to move around while shooting. Any other suggestions around the same price?

3. Tamron 17-50 f/2.8 vs Sigma 18-50 f/2.8? I realize that the tamron is going to be a bit sharper, but is it worth the extra 200 bucks or so? also, im going to be shooting a bit in low light conditions. going to be shooting mostly skiing and skating.

4. Lastly, what is a good/ cheap zoom lens? I know most of you are going to tell me to go to the lens thread, but most of the things on there are a bit more then I want to spend.

I'm a bit tight on money, but def dont wanna cheap out on this. I could do with one lens for a bit, but would enjoy another zoom.

Thanks much! +K for help