I decided to do some cosmetic updates to the house while I am in it (new flooring, paint, appliances, counter top then staged it with new furniture) all with the idea to flip it.

Do I also get to depreciation furniture and shared items purchased in common areas?

A/C units, appliances, furniture, all that is much more expensive.  

However even if they have one piece of furniture inside still, I would consider it occupied. what does your lease say about abandonment?

I haven't made any moves towards an attorney being how the tenant moved out on her own will, problem is is she hasn't turned in the keys for the old locks and still has a bunch of junk and furniture there.

The cost for furniture and pictures?  

I have not thrown in other things like the cost of getting the house ready to rent, legal fees, accountant fees for filing taxes, advertising fees, costs of furnishing the house with beds, TV, maybe even cook ware or appliances, and regular furniture. 

If it's due to the size, then there's potentially a lot of furniture.

I currently have problems with issues of smoking in the house (violated lease), noticed damage to the front door's lock, leaving old furniture in the back yard (killing a big spot of grass, because it was laying there for about a month or 2), getting notices from the HOA about neighbors complaining of possible illegal activities at the unit.  

With furniture and belongings, deficiencies can be difficult to see.I would explain to the new tenant that they are agreeing to use the original condition report from before they moved in, and get their signature to that effect.I would explain to the leaving tenant that the deposit stays with the new lease and they should work with the new tenant to get any desired refund from them rather than you.Otherwise everyone moves out and you start all over with deposits and condition reports while it is empty.