I haven't logged on in a while).I ended up upgrading the ancient hot water heater to an on demand gas unit.

Lying under a sink wrestling with getting ancient faucets loose is really getting old. 

A buddy walking with a cell phone is not going to know if roof is good, electric panel is ancient, if the foundation is sinking, you may need to go there when you do not have the tools in play.

@Scott M Dorau the 1% rule is what our forefathers used to evaluate deals in ancient times ;).

You might see a failing foundation, water intrusion, rotted joists, ancient water / waste lines and who knows how many other red flags.In the attic, I look for knob & tube wiring, missing or insufficient insulation, leaks, crumbling chimneys, etc.To have both of those areas off limits would be an absolute deal breaker for me - and shame on your Realtor, who is supposed to be your fiduciary! 

Tiles totally full of ancient biomass. 

At that point, look for a house hack that needs normal cosmetic repairs (flooring/paint/patching drywall/etc) but DO NOT take on a full gut job where it needs everything (roof/structure repairs/outdated electrical/ancient furnace/etc).

But I’m ready for bigger investments and in my area the biggest deal you will find might be a 6-7 unit ancient house that’s been chopped up into one bedroom apartments.

I don't want to spend a day and a half writing out my exit strategy, but yes, I want out of ancient Yinzerburgh crapshacks and their typical denizens. 

If the house is not far out of level and it is mostly soft flooring from termite damage to the ancient floor joists, then, you can sub-contract out the JOB a piece at a time.