I have a fairly large vb 3.8 forum to import. I installed XF and have been configuring and installing add-ons. I just realized something though, I have gone in and created some forums that I don't have in the vb installation. I haven't imported anything from vb yet. When I go to import vb will XF look to keep the same forumID's intact? Meaning, should I go back and delete all the forums I just created so that there are no forumID's stored in XF before the import to prevent conflicts?
Since I'm on the subject of importing - my site's avatars are a bit larger than the stock XF sizes... most are about 170px wide and are wider than they are tall. What will XF try and do with them? Just display them at a smaller width and force them square? Will any cropping occur?
And I've been wanting to say this for a little while now, you guys rock. I'm sure others (who have been doing this for over a decade like I have) will probably agree, this atmosphere feels a lot like the early vB days (pre 3.0). It makes me feel really comfortable with the transition and I'm hoping things stay on this course. Lots of excitement and helpful people around here. It's making it fun to play with forum software again.
Avatars will be adapted to XF's sizes. This involves resizing and cropping as necessary.
If by the admin you mean the user you created during installation, you can't remove that -- presumably it's your only user so you have to keep it. The default forums (category and forum) will be removed automatically if you maintain IDs.