The terms vary greatly with seller financing, as they depend on what you negotiate with the seller. 

I wouldn't rely on the 50% rule as the expense ratio can vary - I've seen anywhere from 30% - 60%+ all depends on the product type, class, age/quality/condition, market, who pays utilities, etc.Generally speaking for B/C product built in the 60'-70's and 70+ units I've seen expenses range from $3,700-4,500/unit per year.

In any market, some landlords are going to list way too low, some too high, and properties vary widely in grade, layout, block, and other factors that rentometer data does not calculate well into the results produced. 

The loan terms, rates and length with vary depending on the type of properties you own.

It's a great place to connect with people with varying interests and backgrounds.

You mentioned something important which is that you use data from your portfolio, and as a new investor I'm guessing on expenditures, sure there are guides but they vary based on market location.

This may also vary by market but I'd never expect a tenant to check on a boiler let alone light the pilot. 

If you include on your closing statements (which vary state to state - HUD-1/ALTA statement ) the renovation costs - and have them charged at closing......

Hello:It varies by lender. 

The interest rates on non-owner occ are usually higher, but the rest of your statements can vary with each lender.