I've painted bead-board below the chair rail 

Reasonable is about 15% over all costs, some leeway can be added, it is a judgment call but they don't really care what you make, they want to know the seller didn't land a naïve buyer who overpaid in a property with an inflated sale price, if it's reasonable and justified you should have no problems. :)

Your tenants will probably tell you which improvements are important to them rather than having you guess what would be added value.

The cost of the septic and improvement would then be added, less depreciation.SInce the home is modular, can it be moved?

Would also be adding to this as I gradually clarify my aims and as my understanding increases.Good luck and all contributions greatly appreciated.

Would the umbrella insurance be added to the mortgage payment, or would it be something I would have to pay for seperately?

I went through my material list (200+ line items) and here's just a taste for you:Paint, primer, windows, doors, dry wall, mud, tape, screws, corner bead, door knobs, door stops, closet shelves, closet hanger rods, baseboard, door casing, ceiling fans, ceiling lights, switches, outlets, cover plates, CO & smoke detectors, underlayment, underlayment screws, thin-set, grout, tile spacers, tile, grout sealer, sanded caulk, cabinets, vanities, faucets, sinks, toe kick, filler boards, counter tops, garbage disposal, water lines, plumbing lines, drain kits, valves, mirrors, towel rods, tp holders, bathtub, shower pan, tub/shower faucets/valves, toilets, wax rings for toilets, dryer vent, floor/ceiling vents, tack strips, carpet

If you pay high buy option for a property it will eventually be added to the basics after you exercise it, so does not matter.

I requested to be added to the rei group and I got an email that I was accepted.

Interest only, investors, combined with a construction loan so the interest can be added to the construction loan, etc.