1) at $23k there isn't a lot of room to negotiate down especially since there are closing costs and the seller has to move, so I'm not surprised they won't go down. 2) from the description it sounds like it needs a lot of work and adding a closet (literally just some studs, drywall and a door) is not going to cost much if you do it while you are tearing up, replacing and fixing up everything else.Are you sure the issue isn't just that it's your first and you are getting nervous? 

We purchased a house, listed it for rent a few days after closing, and had the following work done: Painting (interior of house) - $4,220Plumbing and electrical work - $1,603Countertops - $2,130Flooring - $5,800Garage Door - $8501.)  

What should I do?  Or

If they scratch a wall or dent the door, charge them for it.I manage over 300 rentals and get at least one tenant a year trying to pull the "mold card" on me.

However, if you are a now realtor knocks on a door or leave a flyer with no hand bill permit or local solicitation permit you may be fined by that city in most towns or cities.

It opens up many more doors.

The reason I prompt this question is because, I'm looking at a quad right now in the Jacksonville, FL area that appears to shake out to about a 10% ROI and around $134 per door.

we thought of going there and ringing door bell, no answer have locksmith open.

We manage them ourselves and we should be cash-flowing around 100 dollars a door.

@Wave Taylor  A dwelling unit does not need to have two (2) doors pass code.