It may be too early on to be trying to structure ourself this way, but I feel like if we create our system now each door will be easier to add to it later.I’ve read about a lot of different strategies including: - Keep the houses in your name, use an umbrella policy (which we have) - Series LLC (Delaware) - Real Estate / Land TrustMy wife and I currently reside in Massachusetts and the fees for businesses aren’t cheap (LLC’s are somewhere around $500).

While you are legally correct, attitudes in the court system, and the particular judge, will determine what happens.

They are also the ones that helped the existing owners flip the house this year so have some history with the property.Re: condition of systems - window air units so no HVAC.

I would look into a subject-to because then you can hold the property until the 14 months is up and then if for some reason the house isn't worth it or the system takes a dive late next year, you're even more covered. 

I've looked into a new HVAC system but it doesn't seem feasible.any help is much appreciated!

Any suggestions on seller friendly appraisers that do work outside of the bank system?

Its market and local code dependant for all other then the (in my view and most code) the GFI's in the bath, kitchen, exterior/garage/basement outlets.Buying an older house has more expenses vs post 1970 which is when most systems are all up to snuff;  plumbing is largely copper, decent circuit breaker boxes and amperage power feeds from the street, sewer largely PVC...   

I would consider the following (which you may have already done):House rules say no gatherings (penalty of $X per person if violated)House rules say quiet hours are 10:00 PM - 8:00 AMIf profile has no reviews / not verified, require they confirm the # of people who will be at the property & agesUse a noise monitoring system like Minut or Noiseaware (disclose in listing)Use exterior cameras to monitor driveway (disclose in listing)But at the end of the day, there are still bad guests who will get through and sometimes you just have to file a claim, kick them out, apologize to neighbors, and get the place ready for the next group.

I didn't realize we were walking into such outdated operations or I would have prepared my own system.

Developing systems to source solid off market deals will help open doors to other things you need to ultimately be successful.