Those things can be really costly if found to be needing replacing, and the sooner you know about them, the better.Yes, you will definitely want to see what kinds of permits you will need, easier than having to tear down anything you do, and start over.   

@Chris Hamrick  it would need to be contractors but if you have to replace a heating system or do major work you are going to use a contractor correct? 

And their replacement portion needs to be treated as investment - so rented to you. 

I have yet to have to replace flooring due to kids going to the bathroom on the floor haha 

Good Day,We are investors doing flipping n rental and are looking for proposals for licensed and insured contractors in the area of Clearwater, FL .We prefer to work in tradesmen and handymen instead of general contractors.The tradesmen we need are the following:o Drywall installerso General Handymano Painterso Floor installerso Kitchen▪ Kitchen remodeling company (they do it all)▪ kitchen installers (we source the materials they install)▪ Granite/Quartz installer (we source the materials they install)o Landscapero Plumbero Electrician● Pool -o Resurface steps since probably not replaceable-will find right subo Clean up the bottomo Filter housing & pump replacementIf you are interested please let us know your proposal and if have any contractors referrals that would be great¡¡Thanks in Advance,Have a great day

The rehab consisted of replacing the roof, changing the floor, doing a new kitchen, updating bathroom vanities, and painting the entire house. 

The rehab consisted of replacing the roof, changing the floor, doing a new kitchen, updating bathroom vanities, and painting the entire house.

If it's knob and tube you'll probably want to replace it.

The rehab consisted of replacing the roof, changing the floor, doing a new kitchen, updating bathroom vanities, and painting the entire house.

You can let them know your house rules but if someone throws a fit or is non-compliant it may be best to endure it if it is not too bad and look at replacing them when the lease is up.