Currently the water heater is vented through the chimney- there's no fireplace in this place I'm looking at.

Ok so it's a 3bd, 2.5bath, 2car garage, and a working like new fireplace(owners don't use it) in a Great area.

Some have fireplaces, but I take out wood burning stoves. 

Not sure what to do about wood paneling on walls & brick fireplace.

Fireplace?

Former mansion of its day with all original woodwork, fireplaces with modern conveniences, great location and rental history.

Well, direct vent gas fireplace with the blower is a heat source and you can have one in every room, no variances needed.

Hi Laura,I personally prefer to live in house with no trees blocking it's view from the front yard, but a lot of people (as you can see from the posts) like trees in the yard (some like the house almost totally obfuscated and will plant even more).So if it were mine, I'd leave the trees for that reason, and just darken the shutters to a dark chocolate color, leave the paint as is (if it's in average condition), leave the fake well because it seems to match the structure and not detract from it (if new owners don't like it they can remove it easily) and take the shrubs down to foundation height to make the house look bigger.But if I were living there myself, those trees would be firewood for that fireplace (something your Realtor could point out to prospective buyers).

Immediately investigated to find out they had removed GAS logs from fireplace and were burning wood! 

The fire place door needs replaced, new molding around a door, painted when not approved and they tried to add new flooring only to put wood floors in the living room and hallway with no transfer strips to the carpeted bedrooms.