If you use that import option (to preserve source ids) then it must be a brand new installation with no content or you will get duplicate key errors.
Doing physical deletes with queries is problematic because there are many joined tables involved, and if your deletion isn't complete then you will still get duplicate key errors due to orphaned records that you failed to delete.
If I were in your situation, I'd start from scratch with a fresh install. No need to preserve accounts of any Admins who let the forum get to that state anyway, right?
If I were in your situation, I'd start from scratch with a fresh install. No need to preserve accounts of any Admins who let the forum get to that state anyway, right?
I think he meant admin as original admin account. And this would be a very handy feature if you want to keep all your usergroups permissions and template edits and whatnot.