I didn't have any experience with this type of thing, but I will be on the lookout for it in the future.Drain pipes for plumbing were old and some were in bad shape.

I did a full rehab on this property including landscaping, new flooring, fresh paint, new kitchen, new plumbing, new bathrooms, etc.

I've seen all sorts of plumbing issues but have never encountered it.

This could be a bid from a contractor to fix items such as roofs, driveways, plumbing, etc or it could be financial numbers showing their income vs comps of other recently sold, to show why your valuation is far off. 

I had some questions for the sellers about how long term the tenants were as well as some major capex questions due to the house being 100 years old (concerns about condition of slate roof, wiring, plumbing, etc.). 

Floors, drywall, electric, roof, maybe plumbing, but I’m no expert and can not evaluate these things myself.

This will help you get a better idea of what tile, hardwood, carpet, plumbing fixtures and light fixtures costs for your rehabs.#3 Contact Local Contractors for PricingCall local Subcontractors and get budget pricing for common repairs on your typical rehab project.  

Most flippers in Milwaukee make only 10-20% gross profit - and they usually don't touch systems that have some life left and will pass inspection (like plumbing inside the walls), which as a long term owner you want to take care of as long as you have the walls open - and not come back in 5 years and rip out the brand new kitchen..   

If you aren't moving wiring or rerouting plumbing, a license just isn't needed.

I do not have direct experience with leasing to tenants involved in domestic violence, but am aware that there may be special considerations involved in California.