1. A character of any level can purchase a house, provided that character can afford it.
2. Lots. And Lots. And Lots. The price depends on location, and directly varies with the recommended level range for that server. Think in the hundreds of thousands range.
3. Well, you can get houses that look like all sorts of things on the outside, and use various tilesets... I think we're getting some more interesting stuff in V3 - keep an eye out.
4. The doors have DC 121 locks on them - unpickable. They're accessed via a conversation, and you must have the key in your inventory to be able to open the door, which then shuts after several seconds. The only way someone can get in is with a key, or if someone either inside or who already has a key opens the door for them.
5. Oh yes. However, you have to purchase containers to put in there...
6. Which brings us to this question, the answer to which is yes (if I understand the question correctly). While you buy specific houses through the Real Estate Merchants, the furniture you put in there is entirely up to you. You buy deeds and place them yourself - half the fun is furnishing your place.
7. There are VERY few (if any) houses available currently.
8.
Shamur Reatur. *Laughs.* The answer, really, is no, though you can ask someone to help you set things up. HOWEVER! Keep in mind that any placables placed by someone else belong, in the eyes of the database, to that other person.