i have some questions, if you'll entertain them
1) do i download the full 7.1.1 version from
the member's area? or do i get the importer from threads 6.5.x?
You will want the full (latest) version and the importer; you will need both.
2) its been awhile since i've put in a new version -- do i clear out my ubbthreads folder first, and just upload all the clean files? ...and does that depend on how you answer question #1?
Going from 6.x to 7.x isn't an upgrade; it's a seperate install with an import of your 6.x board; theres an upgrade guide
hereRE: Hacks; I don't think any of those are in 7 (as stock or as mods).