If I purchased a 3 flat and I'm living in one of the units of a 3 flat, what's stopping me from moving out in 6 months, renting that unit, and then applying for a mortgage with another lender?

See, the landlord has to apply to the state's attorney general, and they will look at the occupancy.

I'm just about your age too, I started with a Capital One as my first credit card, then opened a Citi Card as well, if they see you paying off your balance in full every month they will gladly increase your limit and you will start getting tons of cards in the mail, don't go too crazy though as applying for too many cards in a short period of time will negatively impact your credit score. 

I don't expect to see any sort of return for several years, but it seems nice that other people will be paying for my property for get better.If I were to finance 100% of it the P&i would be just about 1000 for 15 yearsI'm trying to apply the 50% rule.

As far as the utilities, you can apply a proportional billing based on square footage.

If they want more than that, they you way want to walk away.You do want to look for two things, either cash flow (will the property rent for more than PITI + expenses including maintenence)or you want to get a bunch of equityor both equity and cash flowYou can make money in any of the above casesMAO only applies if you need to do repairs to rent it   Most of the property that you will look at subject-to is lived in my the owner or was recently lived in.

The 80/20 rule applies in the miltiary also, except it is more like 95/5. 5 % of my sailors I wouldn't let come near my family or properties.

Several months of applying the @Marcia Maynard school of being firm fair and swift brought a turnaround but the essential message is that the signs were there.

If most or all of the following apply, you might want to seriously consider financing that next big depreciating purchase:You have a high tolerance for risk and are able to take on significant leverage. 

But declining an applicant who applied for your rental and you received a credit report stating they had bad credit, is based on facts that you actually paid money to receive about this tenant.