so let me answer Your questions:
Regarding the second part of Your questions, the Group tab of the BOM is intended to build sorted groups of Your BOM entries depending on a sort/order criteria.
For every cirteria/group You can define header lines before and bottom lines after the group of elements.
IMHO the handling of that group tab is not very intuitive and usefull, the idea behind is great!
The groups are there so you can do things like this......it's become very valuable for purposes of manufacturing and especially sourcing for purchased parts for us...
@nominus38, How did you use groups to do that? Can you do a video on your workflow? To me, this is a remote, arcane, area of SE. I'd love to see how to use it.
@bshand Well, it might be easier if I just sent you some parts and maybe one of my B.O.M.s so you can look for yourself.....I don't know that I have time to go thru and show the entire workflow from scratch......
@bshand download this attached zip quick, I'm gonna delete this in a few minutes. The only way I can think of to send this.