The Realtor I'm working with is great, and on our most recent BRRRR, I feel like I underpaid him for the amount of work he did (particularly for the extra effort and work he did after the acquisition - communication with the contractor, photos, status/progress updates, market analysis). 

You might want to share your analysis sheet with us.Is this a high-appreciation area or something?

Find a cure for analysis paralysis.

Lastly, how about decluttering (yes even with a tenant in place), and taking professional photography, or virtually staging, or at the very least opening the blinds and photographing during the day.

I agree with the analysis above, but I just want to add that if the rental was illegal, as someone above has suggested, then you will be unable to collect any arrears that are owed.

Personally, I love BRRRR, and you have to learn the ropes on analysis and due diligence (for starters). 

This is at a pre approval stage so there is no real commitment until they submit an offer, sign and commit to a broker. 

6.6% cash on cash is nothing to write home about.Without posting the details of the property analysis, it is impossible for us to offer much help.

It's no different than any other loan - lending is based on the analysis of the property.

If there's a hole, it may be a red flag.b) sensitivity analysis: I examine all the assumptions, and make sure I can live with the worst case scenarios.c) "Stall and see": if they are getting money over multiple years, and there is no penalty for investing later, I would usually wait so I get some real performance data, versus having to look at theoretical pro forma information.d) Recession stress test: I will not invest in anything, until I subject it to recession level stress and see if I can live with the result.