Here's my results for the Tricky and Taxing levels in this challenge. For an extra degree of difficulty, I did the max-% solutions for all of these. I also added one of my own favorite challenges to the mix in Taxing 15 100% No Builders.
Tricky 19: 1 attempt
Tricky 22 100%: 2 attempts
Tricky 24 100% 2 attempts
Tricky 25 100%: 8 attempts
Taxing 3: 1 attempt
Taxing 11: 1 attempt
Taxing 14 100%: 2 attempts - in the first attempt, I placed my basher through Nessy too high, resulting in a splat fall off of Nessy's nose.
Taxing 15 100%, No Builders: 14 attempts - The successful attempt was blooper-fest, yet I somehow managed to pull it off. I let a digger go too far and ended up having to redo a section of work that had previously been completed. Later on a miner turned off a blocker that he was supposed to free, resulting in even more skill wastage. I ended up using all 20 bashers, all 20 miners, 19 of 20 diggers, and the last lemming exited with 6 seconds left on the clock.
Taxing 16 100%: 6 attempts - There's a bunch of frantic building early on in this one, but it's fairly simple after that.
Taxing 22 100% (2 solutions): - 1 attempt for the direct route (send a floater down and have him build a catch-bridge for the others); 3 attempts for the "over-the-top" route.
Taxing 24 100% 1 attempt
Taxing 26 100%: 5 attempts - I technically got this on the first attempt, but I used all 12 builders in doing so. To be fair, I kept trying until I got the builders down to 10, to meet Amiga requirements.
Taxing 28 70/80: 29 attempts - This one is tough even when pausing is allowed! There were a couple of spots in which I had to assign basher then builder in rapid succession, requiring a rapid-fire click-F7-click sequence. I'd be truly shocked if anyone could pull this one off without using the keyboard.