This is the story of all the errors...
Everything going alone fine... then:
FIRST: didn't make input and framework different geometrical sets. Bad news bears.
Second: was selecting the multi-section mesh as powercopy instead of the whole geometrical set. Rookie mistake. This wasted a good hour or two completely rebuilding. and rebuilding. and rebuilding.
Then: powercopies: success! yay happy AL.
Then... oh wait.
The evil sweep operator came along. Had paused the tutorial so I didn't continue watching to see that you had the EXACT same errors, but I basically went though and rebuilt that one sketch/fixed it blah blah.
but oh wait. more errors:
by this point I figured out that I needed to watch the rest of the tutorial and found how to reverse the offset. Easy enough.
This is how far I got: all the other powercopies kept erroring but I know how to fix one so I figured it wasn't necessary to fix them all. Yay learning through messing up...