1. tk2d doesn't allow you to resize the tilemap once created, but you can create a max size map (1024x1024) and leave it like that, you only pay the price for the tiles you use.
2. You can make it isometric, but the buildings etc should be sprites on top of it for sorting reasons.
3. You have to handle the replication yourself.
4. Docs here -
http://2dtoolkit.com/docs/latest/html/classtk2d_tile_map.html you can create / modify the tilemap in code.
5. You can have isometric tiles in tk2d, but sorting will likely be an issue if you have overlapping tiles.
6. tk2d tilemap layers al sort together - they are optimized to one object. Performance is optimal, but if you need complicated sorting this might not be the best option.
7. Nope, the tilemap has a sprite collection assigned to it, you can either change that, or the associated material and/or texture directly.