I see I made a major deficiency in purchasing my current property with the age of the key items, e.g. gas furnaces, water heaters, washer/dryers, refrigerators, stoves, plumbing, electrical, etc.

That's a great idea but have never heard of where you could get this info.See if power, gas or water companies would tell you.

Keep in mind we do not have known cost amounts for these repair items, and can just make estimates, and hope no other costly issues are uncovered after attacking some of the repairs.My question is, with our next interaction with the selling agent, should we:A) Ask for the major repairs be metB) Ask for a decrease in agreed upon price (without great idea of what the repairs will cost)C) A combination of both; settle with some repairs met, and a decrease in priceOur entire list is below: (keep in mind that I am not sure if all of these things need direct attention to get the unit rent-able, or if some items can be overlooked for now and deal with later as they become more of a problem)Repair List:Items that need attention before renting unit:Big Ticket Items:Install furnaceInstall all new appliancesInstall water heaterExterior electric power supply is damaged, needs repairInstall guttersNo termite treatmentNo gas meter, install newAttic decking has moisture damage, needs repairSmaller Repair Items:Install electric panel faceplate and secure exposed wiresTwo prong outlets (could not test), swap out, install GFCI where neededTrim tree limbs in contact with power linesMissing light cover under front entranceRepair kitchen windowsRepair kitchen sink leakRepair utility room leakInsulate atticSeal gaps in living room doorLoose bathroom faucetAdjust shower water pressurePatchwork performed in multiple rooms, walls are plaster on wood lathe- which I have been told can have asbestos issues once opened upDeferred Cost Items:Large tree removalTorn and missing roof shinglesSeal plumbing boots on roofRaised soffit under car portSecure electrical lines in attic, they run over attic stringers, not through them (necessary?)

I believe gas takes longer to heat the water but more cost efficient but don't hold me it.From google search:The average American shower uses 17.2 gallons (65.1 liters) and lasts for 8.2 minutes at average flow rate of 2.1 gallons per minute (gpm) (7.9 lpm).

(example:  you might frint the cost for gas, but then enter into an agreement with the gas company to earn money back as new houses come on line and use gas).

I'm currently the GM for a welding automation company in the Oil & Gas market that is tied into a larger international manufacturing group. 

It is an electric mower (again not a huge yard and would be worried about the pricier gas mowers and someone not using right) but that leaves possibility of them running over the cord. 

Instal gas fireplace?

. $2.50 to $3.50 gas (depending on where you are), interest rates at historic lows.I have to say, if you are looking at MLS, you are NOT going to find DEALS.

Usually, something of that age would be natural gas in western PA.