How much to cut out LS2 pan?
#2
Your best bet would be to buy one specifically for the swap you are doing. There is a lot more to it than just cut and re-weld. If you have the facilities and are very experienced it is do-able. If not it turns into a real nightmare working with cut and rebuilding the pans. Check the search there are a few guys here who have done this swap and there are sponsors here who sell swap parts that are specific to the platform you are working with.
#3
It all depends on where you put the motor in the engine bay. You would be best off sitting the engine in the mounts with your steering linkage not hooked up. Hook up your steering linkage and mark your pan. Make sure you leave extra room between the pan and linkage.