Although I agree that it is standard for anyone over 20% equity to have to sign on the loan, as you said maybe there are lenders who are more flexible.

First I would like to see how much I can borrow for a house hack or just standard rental property investment and see what my options are.I’ve got about 30k +30k loan on my 401k.What do people recommend?

Get their standard contract and compareTalk with your local police.  

Used and agent with a standard deal.

The situation for international investor is similar as for US resident for ECI (Effectively Connected Income, eg buying and operating real estate directly) when it comes to US taxes but it depends on country of residence to determine if local tax.For FDAP (Fixed Determined Payments, eg dividends from investing as limited partner, receiving dividends from REIT...)

Depends on your situation which would work out best.On the selling side, again you have two main options, list for $1M with a listing commission % (of whatever you choose) and still offer selling agent commission as standard for your area, or option 2, list with no list commission and lower your price by the commission amount it would have been to attract more buyers at a "lower list price".I have done both and it was all situation dependent.

Ya but it’s not like wholesalers are actually held to any standard at all, like realtors are.

etc.)Is using sites like craigslist and Facebook worth it or should I just stick to Zillow since they handle all of the applications internally?

When I am evaluating a property you have the standard PITI = Principal, Interest, Taxes and Insurance. 

My company has very extensive internal reports on market revenue expectations, so finding a rep in the area you are looking, and contacting my company to get connected with that rep would be a free option as well.