1. an incident report will be in your record, but not going to change your premium much if your first claim.
2. you should call your agent before you file the claim, most experianced agent should able tell you what your coverages are, they always kept a copy of your policy in file.
3. normally if water suck away pretty fast, drywall should not be an issue, if tenant insisted, you can cut a section out along with base to confirm that. as to wood floor, laminate, they are gone once in water. vinyl is best for kitchen.