I tend to estimate vacancy higher than 4%. 

The idea behind the 75% was that 25% was estimated to go towards repairs, vacancy, CapEx etc.Also, as mentioned above 1-4 unit is residential and 5+ is commercial.

Should they be sending me pricing, ARV, repair estimates, etc?

Is there a reason you have these estimates at these numbers? 

Ask your trusted contractor& another 2 more contractors to walk through with you and estimate the cost of fix 1st to see if it is within your Budget and time.  

Hey @Jamal Abodalo, are you super-confident in your rehab estimate?

When I'm sifting through potential investments I do a simple rough estimate using the 4 square system to evaluate the potential cash flow.

Note that costs may significantly differ because of accruals, but those are all estimates anyways, so I would only look at other costs (e.g. title search charge, point fees, etc.).

It means that your estimated PITI should not be above 90% of the projected monthly rental.

So worst-case scenario for doing a sub2 on my parents' place is the bank calls the mortgage due and I refinance, pay the $5k (estimated) in closing costs for the refinance (I'd lower the term, and the loan amount will be less than 80% of the market value) and the mortgage is now in my name, but I still have the equity.