1. You can baste with pins thread or spray.
2. you can use the floor. You don't have access to a church or shop possible to baste?
3. you only have to quilt the distance the batting says. That being said I would do what you feel will look best for the quilt
4. what the package says is the max limit different types of battings have different widths
5. Yes you should have time
6. I would test tension on scraps before starting the real thing and use a fine thread if you really want the SITD to blend in