Just thought I should point out - it appears this pack was compiled with a very old version of the Flexi Toolkit, which as such marks it as not fully compatible with V1.43n line. It will almost certianly still work anyway, but it's something you should fix. All that's needed in most cases is to get the newest version of the toolkit and rebuild the NXP with it.
Anyway, since I can't really record right now (so not going to do NepsterLems or the contest levels), I thought I'd give this a go. I'll get back to you soon with replays and feedback.

EDIT:
Some of these levels need the steel areas to be fixed up, eg. Fun 10. I don't know how accurate SuperLemmini's placement of them is, but for most levels, this can be handled simply by turning "Autosteel" and "Ignore Manual Steel" on (you can use the "Force Autosteel" option under Show All Options in the Flexi Toolkit to apply these to all levels).
Tricky 9 / Mayhem 6 and Mayhem 1 additionally require the use of the "Simple Autosteel" option to work properly. There may be other levels where this is the case too, generally any that have decorative terrain like moss overlaid on steel.
Tricky 4 / Taxing 7 is a total mess in regards to steel, and I would recommend simply re-making these levels if nessecary using the NeoLemmix versions as a starting point.