Here are my replays! I'm generally not good at beating very difficult levels, so after playing them, I think the levels are really fitting your goals of making it a Tricky-Taxing pack; the levels are not too hard, but not overly trivial either. I got the talisman for Level 2, and Level 5 particularly stumped me until I figured out the solution, which was clever!
Don't feel bad about your first pack not being as great as you wanted it to be. It's understandable that some of the levels did not turn out the way you want it to be. I've been there; I've made levels in the past for another Lemmings engine that I thought were fun, but looking back now, they looked really bad, and out of that bunch I've made, only few of those levels were remade for my NeoLemmix pack. Up to now, I still make levels that turn out to be bad-to-mediocre; when this happens, I put them in a rejected folder.
It's okay to make mistakes as well, as the point of mistakes is so we can learn from them, and as such improve from them. You've even identified a list of things went wrong with your first pack, and that's a very good first step in knowing what you can do to improve your pack. Take your time when creating this pack, and let us know if you need any help with testing levels.
Looking forward to the pack when it comes out!