My issue is, I have not found a simple way to record the breakdown of the rent into these categories.

It seems simple, but they can screw it up easy

So the double booking issue was actually a result of poor practices on my part and a simple fix.

I know over simplification: nothing is simple. 

Daniel, a few thoughts I had:Since the DTI is the issue, income is too low or debt is too high...Can you refinance the other "cash flowing rentals" assuming either there is equity to capture OR an interest rate you can slash.

I'd keep it simple here:1.

It's important to have some sort of lead capture system. 

I like to have the lender call the listing agent directly to vouch for the pre-approval letter so they've heard a human voice and know it's not some unreachable person.As far as listing a house that needs updates, make it as clean and uncluttered as possible inside and out, we always stage (can be simple and DIY, makes a big difference) and do pro photos, and figure out what the house has going for it and what it could have that buyers love (great yard?

it feasable to assume I can always add it all back together if I am ready to sell to capture appreciation?

My simple advice is to buy it if it has real value to you and your family regardless of potential rental income.