I have buyers who don't know what or where they are looking so I don't narrow my auto-search down for them other than the basics (2-4 units for example).

Buyers will ask for custom changes. 

And if assign, what happens if you cannot unlicensed broker and find a buyer?

They've gone as far as to deny entry to perspective buyers and hire an attorney.

Not sure how things are out there but I️ would only assume that if you restored it right in a historical fashion and marketed the property to a wealthy buyer who appreciates historic homes then possibly could have a massive deal.

Your tactic is BAD either way and could get you sued especially if the seller can prove you had no intention of closing as the buyer and you try to back out. 

HOWEVER, Buyer A doesn't have $100k... but he has $50k.

I'm selling it for 10000. i asked buyer to pay all closing costs with the cheap price im selling it for (the house is in rough shape but not as rough as comparably priced properties in the area most of those have a bad roof or foundation and this one doesnt its livable actually ).

A lot of deals are never listed and taken directly to known buyers so you need to be on their radar.There's also some syndication opportunities around Indy if you are looking to scale.

You'll still want to talk to your tax man because you could still be at a 15% rate but you'll also have depreciation recapture of 25% so no matter how you go your success is going to bite you if you have to pay tax.At this time in the market if you're wanting to slow down I'd not recommend carrying paper or selling on a land contract.  2-3 years ago I would have done it and then prayed that the buyer goes delinquent.