2
1 and 2 are planned for XOOPS 2.2
(But you already knew that from other threads)
3. I'm not sure if 2.2 will make this possible or not. It should be easier to migrate XOOPS to another DB tho. It's definately planned for XOOPS 3.
4. Depends on the (WYSIWYG) editor used, I guess. If someone implements the spellchecker into a wysiwyg editor (which will be easy to add to a site using X2.2), then it's great
But, IMHO, not nessecarily a core feature.
Herko