This is my solution to your earlier version of the 6 builder, floaterless challenge. I see you managed to save the blocker at left by conserving the terrain removal skills at the right to eventually improve it to lose 7.
I almost got a 5 builder, floaterless solution, but alas, it loses 10 lemmings, both off by only 1 or two pixels. If you could move the starting steel block down by 2 pixels, and the entire starting island to the right by 1 pixel, it'd work.
I especially like your 100% solutions; I never thought of using the basher to free the blockers; also the way you free the blocker in the second solution releasing the crowd at the same time is pretty nifty.
Yes, using your 7 builder, floaterless, lose 1 solution as a base, your two mini-challenges are only slight variations of it.
The terrain of this level and the skillset seem to allow for a lot of variation, and it's nice how you've come up with so many solution ideas for this level.