And now, Prima.
Fun
1: Obviously possible since it doesn't give you more than 1 of any skill.
2: Same logic applies here.
3: That logic doesn't quite apply, but the level is still quite simple to do with 1 of each.
4: Also quite easy to see is possible with actual 1-of-each (but not when further also limited to the skills the level gives).
Tricky
1: Quite obviously not possible. Too many obstacles to get past.
2: Quite obviously possible.
3: Possible even when limited to the existing skillset (but limited to 1 of each).
4: Also possible even with the existing skillset. If you give *all* skills, it's not just possible, it's trivial.
Taxing
1: Obviously not possible as many builders are required.
2: Possible with existing skillset, though requires good knowledge of the level (or lots of trial-and-error). Trivial with actual 1-of-all.
3: Doesn't seem to be possible.
4: Obviously not possible as at least two (maybe three?) builders are required.
Mayhem
1: Only gives you one of each skill at most, so clearly possible.
2: Obviously not possible. Requires either an unsaveable blocker to turn around (and the level needs 100%), or multiple builders.
3: Very trivial, though not possible with the existing skillset.
4: Not possible due to needing multiple builders.
So the final list for Prima is:
Fun: All
Tricky: 2, 3, 4
Taxing: 2
Mayhem: 1, 3