Adam
The reason i was able to do it quick is because I only animated four frames (all that was needed) and I lowered the render quality to final and reduced the output size.
I had a 64 bit installation last year but changed back to 32 bit due to too many issues of campatability, Since then many apps have begun supporting 64 bit, I plan to upgrade to a new I7 dual quad soon which will be a 64 bit rig. So in answering you I would say yes 32 bit rendering will be slightly slower, however I use 5 rigs on a render cow configuration which makes the difference un-noticable.
The .skp importer works okay (not great) I still prefer using .3ds export, but that's more because I am stuck in a tested workflow.
Please ask me anything, I will do my best to help.