I watched the first video, if the next two are anything like the first, they aren't very helpful. Got a link to the tutorial that might clue me in better? It looks familiar but youtube obscures the link. This is one of the reasons I think youtube sets people up to fail. It's possible to say a lot of stuff but not really…
Ahh good, glad that helped. In the "lookat constraint" "Select Up Node" uncheck world and set it to target the object its looking at. I don't think that was included in the tutorial because the "world" option was added in max2009 or 2010 and checked on by default. So you have to go in and set it like it would normally…
It looks like you solved the rotation problem in first video? In the second video, it looks like you want to rotate the entire leg from the base? You can do this by adding a parent to your leg bone, a dummy or a point helper should work pretty well. You'll rotate the helper to control the angle of the leg and move the tip…