Yes.
This depends. First off, it would need to be an AT&T model, as Verizon models do not use a SIM card. Also, it depends on the UK carrier. Most would be compatible with AT&T's network, so yes, you should be able to use a US iPad 2 with a UK SIM. Although, take note that the iPad uses a microSIM, so the UK SIM card will have to be cut down to fit into the iPad.
No.
no
The iPad made life easier because the iPad has apps that help you with homework you can listen to music,play games the iPad 3 is not that very great my mom said that this iPad, when you use it a lot the bottom of it burns the iPad 2 works when you use it a lot Plus the iPad 3 cost $500 And the iPad 2 is $400
No u can not
Apple does not make iChat for iPad. But if you have an iPad 2 or newer, you can use FaceTime which is very similar to iChat.
You can use an IPad 2 with no carrier at all if you only use the wireless internet with it or wifi. You can use AT&T or you can use Verizon or just wireless internet.
You can't you need iTunes.
Yes
Yes, but it will be a bit floppy. You will want to put some foam or rubber inside to hold it in place, since the iPad 2 is thinner.
The main difference between the iPad 1 and 2 is that the iPad 2 is thinner and lighter than the iPad 1. The iPad 2 is also faster than the first iPad and the iPad 2 has front and rear cameras.
Both the iPad 2 and New iPad (3) use the same smart cover. They are $49.00 for the neoprene ones, and $79.00 for the leather ones in the US.