Hard money lenders charge 13-15% and 3 points in my area.

The rehab is charged to the project at full cost of labor and materials no discount. 

There are lots of me-types out there that help with turnkey purchases, and they rarely charge to do it.

My plan is to house hack a small 3/4 unit multi-family next spring/summer, preferably with a 5% down conventional loan along with some PMI (assuming the figures work). 

Low demand means that you cannot easily charge significantly higher rent for these units.

They assured me she is being charged late fees, but when she makes a payment all of it goes toward unpaid rent first, late fees last.

For example, if you're LLCing it - which may make sense for a partnership - that'll make it more difficult to get a conventional mortgage.Like anything in real estate, if you're going to be including or working with another individual, you'll want to sit down with a good lawyer and put contracts together that protect both parties in the event that something goes awry.

You'll have to refinance into a conventional loan once you hit 75-80% LTV to get rid of that payment.

For example if you buy properties in certain areas of SoCal you may be charged a premium to due Fire Risk if you are too close to brush areas.

Some cities will charge for back taxes or charge fines for building something against code.