Yes you can export as vCard with N900. However, the problem with this is that 1. I have never been able to get the N900 to successfully export all contact details. Just seems to export name, birthday, facebook page and any notes attached to the contact. Never seems to export phone numbers or email addresses. 2. It exports each contact as a separate vCard and google contacts for some reason only allows you to input a single vCard at a time which is quite annoying.
That is somewhat reassuring. I have only ever used Windows PCs so seems I should not have to much difficulty restoring the Tab if I mess it up. If I go for it I would probably just stick to trying out tons of apps and do much less customising. With the N900 there are virtually no apps so if you want to have fun with the device you are basically left with nothing to do other than customise. However, in case I decide to mess around could you tell me some of the benefits of rooting the Tab.