You have to follow rules such are a mid-month convention and other MACRS rules.

I just lost the contract on a deal as conventional financing let me down too late in the timeline to be able to recover from.

I have discussed my intention with my current mortgage company and they suggested I wait to rent and refinance after I hit the 2 year mark (of primary residency) because I would be able to keep my low 4% rate (conventional loan).

I dont know if MI had finally cycled that inventory as there were thousands upon thousands of homes that met that description but i would say 90% of the US real estate markets are far from this.In fact the opposite.

For conventional refinancing, you'll need to wait a minimum of 6 months.

The new inventory that will be pumped into the markets are Class A/B assets.

Yes, single family properties are less expensive than units if you're talking about conventional financing. 

We plan to offer around 200kWe are thinking about getting a conventional loan at 80% but need to come up with the 20% down plus the money to fix it up- this is where we are having a challenge. 

I am shopping around for conventional loans and am curious what I should expect as far as closing costs. 

If it's a conventional loan, you should be able to go off 75% of the rents on a comp rent schedule unless the lender has overlays.