Pex Piping , no slider or door for rear access from inside the house (have to add a side gate entrance to the rear) No garage, No Dining room. this is a 3/2 1100 per side 2023 build Duplex on 0.3acres inside a neighborhood. what do you think about that?

As a land broker, usually when someone says they want to "build a tiny home on some land one day", it's a pipe dream, and since we are commission-only people, it's scary to spend a lot of time with people who can just change their mind at any time, after we've put in a lot of time holding their hand. 

Here are some that I'm aware of:- Galvanized pipes - typically 40-50 useful life, could rust from the inside out, could get eventual pipe failure- Zinsco or Fed Pacific electric panels w/ aluminum wiring that could be a major fire hazard- Wiring in general (e.g. knob and tube)- Asbestos in the walls- Lead paint- Heating system - boiler?

The plumbing was beyond strange;  the DWV ( drain-waste-vent ) piping was all 1 1/2 inch. 

There are many avenues to exhaust including here, your local REIA and your state multi housing association prior to engaging a paid coach.

There are lots of big $ pitfalls that you can encounter: second mortgage foreclosing, HOA foreclosing, other title issues, IRS liens, collapsed sewer pipes, burst water pipes from improper weatherization, to name a few.Start hereAbsolutely try to contact the borrower pre-foreclosure.  

They did not run the duct outside for the dryer, they just let it exhaust into the kitchen which created the perfect environment for mold.

Its a central heating and air system that disperses hot or cold water to each unit through a network of pipes.

The ponding water was not under any pipes or necessarily near the foundation walls, there was no clear indication from where the water came from. 

We expected that at some point, cast iron pipes of this age would simply need to be replaced or relined - but since there is also confirmed leakage, we would like to do this sooner rather than later.We would like to opt for the less-invasive CIPP re-lining.We have received quotes from 3 different plumbers, all for upwards of $35-45k to reline 70 feet with 16 reinstatements.