Flat rate and leasing fee for SF and % based on project size, property type and scope.  10% seems very high, but 2% is way to low.  

I don't think the physical size of the property is taken into account, if that's what you were asking.Yes, you can exchange 4, $50k properties for 1, $200k property or 2, $100k properties.As an aside, why aim to exchange for a "single property without a mortgage"?

If you add the beds and sq ft i think it would help. if you are targeting that for a 2BR depending on size it may be feasible. 

They're typically small to mid-sized cities without huge amounts of growth.

Depending on the size and location of your sfh rentals, I understand this may not work if you have the need for a big house because of many kids or your rentals are in war zones. 

It's not fenced and it is a decent-sized lot .21.

@Cody GodfreyLots of issues Godfrey.....zoning (is the lot size big enough) utilities......are both props serviced by 1 water line....neighborhood........are ur neighbors going to allowI would advise talking to a good re lawyer who has done this before.

Will County is pretty easy going and still allows romex electrical, Dupage County is pretty good to work with but has a few odd requirements that others don't (like requiring you to upgrade your electrical service to a 200A regardless of the size of the home), and Cook County can be a PITA, but mainly just due to the ridiculous amount of paperwork, and the fact that any contractor needs to go to their office downtown in person for their registration, and they love to send you home without accomplishing what you came in for...Best of luck with the property, hopefully more BP members have some better insight from the Renters perspective...

Also the size of the home is based on "owner" estimates.   

DOM (Days on Market)No comps, or comps are too variedActive vs. pending ratioHigh tax assessment to value ratioInsurance:Property in flood plain or zone and on flood map requiring insuranceCLUE report, uninsurable or difficult to insureInsurance escrow or notLapse, adequacy of coverageProperty:SquattersFunctional ObsolescenceSeptic, onsite systemsWellLead or galvanized plumbingTerracotta sewerProperty preservationStructural damage (expansion cracks, main beams)Landscaping issues: retaining walls, bamboo, soil shifting, etc.No permitsIllegal BR size < 70 sq.