The fastest we can move a SEC 8 tenant in from the time we accept them is 20 days.

If I was you I'd skip the realtor all together and look for off market properties because if you're looking for investing deals, you'll have to go through a LOT of MLS deals and a lot of offers before you get one accepted.

So if your plan has a high probability of success all the way out to age 100, then the probability only increases if you only live to 85 or 90.Also, with younger clients, I tell them to plan as if Social Security will not be there for them at all (note: I do believe it will be around for a long time, though it will likely look different 30 years from now than it does today, which may mean decreased benefits versus what you could expect if you retired tomorrow), and build a successful plan that way.

you need to decide if you are willing to accept this. 

and what rate is acceptable.

I will accept dogs meeting my criteria (Size, Breed, etc)  - but do not accept Cats.

And, if you cannot come to an acceptable resolution, evict the offending tenant as soon as possible. 

The property is low maintenance, the other tenants are all 5+ years in place, the total rent is 2800 and expenses looks to be under 2000 per month.I basically have an offer accepted and a small down payment where do I go from here?

The only scenario that makes sense is that the wholesaler went to the owner and offered higher than the 6% commission, cash, and the owner accepted and canceled the contract with their agent.

You may be the only offer, which means even a much lower offer than asking might be accepted.