The HMLs I've been talking to on the phone offer me loans for a 12 month period.

Here's what we do (copied from our website):Screening ApplicantsPoor screening often results in lost rents, legal & court costs and costly damages.Screening of applicants includes the following:Full credit/eviction/criminal checks are done, instead of score-driven reportsVerification of rental history includes validation of actual property owner to avoid fraudVerification of stability of income & employment via YTD paystubs & W-2(s) (analyzed to confirm not fakes)Income is calculated 3 ways to spot stability anomalies: pay period, YTD average and YTD + W-2 average.Debt-to-income analysis (more accurate than traditional 3x rent requirement)Bank statement to see if NSF issues, if deposits support income, prove MoveIn Funds, also analyzed for unusual transactions.Pet screeningHolding Fee required from approved applicants to make sure they are serious, before your property is marked pending.

The deferment period varies based upon the amount of the loan 5 years then amortizing for 40 years OR Deferred until: ξ the property is no longer the borrower’s primary residence; ξ the property is refinanced under certain circumstances; OR ξ the property is sold or title is otherwise transferredWhat is the best option here?

During the inspection period, I discovered 2 of the other units were 4-8 months behind on rent.

. - The price we agreed is for 2380 sq ft. and the option period has lapsed. - When we put this on rent, can we calculate rent as per 2380?

While if I move forward with conventional financing we'd have to wait 6 months for a "seasoning" period before being able to refinance.

The problem I have is there is a good chance the certificate of occupancy won’t be issued in the 180 day time period.

If you want long term tenants, look for tenants who have a history of renting previous apartments for long periods of time. 

Getting a bit overwhelmed thinking about the Due Diligence period!

@Dustin AllenYeah, this part in the contract confused me a little bit: "...proceeding 30-day period from the execution of this Contract...".