They can take out enough for a down payment for the next house and a little extra to put into savings as a "What if" fund maybe 3-6 months PITI based on the new home payment.

There are restrictions in most places on non-citizens owning property.

I don't doubt they are worth it, but that's money that goes into the non-DIY line panel replacements. 

So I'm focusing on keywords like how much I put down for down-payment.

I'm 24 and have been working a non-RE job for close to two years.

If you ask detailed bids for each items and look across multiple bids, you can confidently estimate the overall rehab cost.In general, the best practice is to pay the contractor across multiple payments - before rehab, during and after.

If that is not enough of a premium for you, raise the premium or non-renew.

Still all  in of about 100-120k assuming you split the down payments with subway on 2 facilities.

My real estate agent talked us up to $1.3MM, same down payment and 6% rate. 

You buy a duplex and your payment is $3000.