We scheduled the home inspection a few days later, which came back clean & had listed the issues we had already identified during the initial walk-through - it was extremely helpful having a REA that also invests in real estate, manages his own properties and knows what to look for during a home inspection. 

The reason is that encourages tenant to pay last month rent and leave you place clean to get their larger deposit back.

All ducts and electrical are in placeMy budget is around 6kPlease help me get an idea of cost, best brands or share referrals for HVAC contractors.Thanks in advance

Already pre-approved.Utilities: Electricity paid by tenants.

I want to have clean documentation so the people renting know the rules and I have something to fall back on when I question is brought up. 

You could use something like this (https://sense.com/) to track electricity and reconcile with the tenant each month...not sure about water though.  

My question really is would you let my current house look like **** being worth at least 350k and hopefully make the new house worth more because it looks so much better or just clean everything up and make both houses look great and raise property value that way?

A contractor that you know and trust with no history of such things is another story, where I would probably just let the contractor know I'd made a note of it and was giving them the benefit of the doubt based on their clean history - further explaining to them that I had to take that action/stance as a gesture to the tenant, and that I value their service.

Duplex tenants would be responsible for landscaping whereas the fourplex will require you to mow the lawn or clean the stairwell and common areas.I would probably take the duplex just because it would attract families with a little more money and probably have fewer complaints of noisy neighbors, parking, etc.

Slate roof (insurance company hated that, I've posted on here before), old galvanized steel or cast iron pipes that were failing piece-by-piece, old electrical with tenants complaining about tripping circuits, cracked foundations and water in the basement, and on and on.