Hmm... I never considered sending a lemming from the left to free the right side. However, it looks like my solution was more efficient in one aspect, which means you can reduce that to 24 skills:
Build over the bear trap to the top of the bridge, and then mine down. This way, you can cover this section with 8 skills (7 builders, 1 miner) rather than 9 (6 builders, 3 bashers).
Looks line almost no one is working on Holiday Lemmings. I actually don't keep track of this thread much, so they may just not be on the list. Here's where I stand for Flurry. Note that these may be improvable.
Some of those can be improved. Here's a few tips:
"Permanent" skills (climber and floater) tend to be weak for this sort of challenge since they only affect one lemming. Evidently, you've noticed this in level 2, otherwise you would have got 15 or so for that level.
You don't need to save 100% unless the level explicitly requires it - though you probably saw this in level 5. (That said, you can get 100% on Flurry 5 with only one skill.)
And there's a neat quirk to level 6. If you look at it in Lemmix (or LemEdit) you might be able to spot this.