It depends on your goals - braces would likely provide a more ideal end result, where invisalign would work for some esthetic correction. I would recommend consultation with your local orthodontist to determine your options as there will be many factors to consider.
This sounds like an issue with the bite based on your comments - please have it assessed as soon as possible - if you are not getting a return call, either go there or see another dentist but the problem will not likely get better while you are waiting. Good luck
Definitely Emax for what you see in the smile (most esthetic), Zirconia for the molars (much stronger, less esthetic). It does depend on the bite, but generally this is the best scenario.
Invisalign will absolutely work with crowns, with the added benefit that you may not need to bond anything to the crowns which can damage the finish and may be an issue for crowns on the front teeth.
The iTero scanner is used for invisalign treatment and is very accurate. Sometimes there is a discrepancy between how the teeth move and what the aligner wants the tooth to do. The scan is going to be accurate if it is completed, I have had a scanner for 3 years and have never had an issue with the scanner itself, but sometimes a little tweak to keep treatment progressing is needed. The next set of aligners should fit well. Good luck
