1. NHL is so much ahead so it's not worth talking about it.
Since the war started KHL is probably not the top leauge in europe anymore.
Some thoughts:
Goalies: Best in the AHL. Since there are basically NHL-backups or up & coming NHLers.
Offensive players: Best in NLA. Salaries after taxes are highest in the NLA, and the league is tilted on offense. Hence, the stars end up there.
Best All Star team: Probably AHL. It would technically be a team of almost NHLers.
Overall teams: SHL. The league is very balanced in terms of player quality and the top players are usually close to NHL capable. It pays better than liiga so many of good finnish players often end up here.
If you use the CHL as reference for the euro leauges it's probably SHL, Liiga and then NLA. Liiga beats NLA thanks to team balance. I don't remember who said it, but I remember an interview with a top AHL scorer who failed in the SHL who said that he didn't expect the leauge to be so hard and especially the bottom 6ers in the AHL are way less skilled than the bottom 6ers in the SHL.