Today she parked back there again and I blocked the driveway out. 

Now 20+ years later, dad is dead and my brother needed to use that driveway and the gentleman went out, tried stopping him and then blocked entrance onto my moms property from her own driveway claiming he owned it.

They have every ability to block the lot split and the sales, since your land is pledged as collateral to their loan.I am not a 1031 expert, but I believe the sales would not be eligible for 1031, since the entire intent of the deal is to flip at least part of the property.  

Around here, I feel like neighborhoods can go block to block.

Most investors once they get to around 5 or more properties they refinance the block of loans under a commercial loan using their LLC/Business and then those loans do not report to credit because they would all be grouped under a blanket loan.If your lender is stopping you form buying another home and you only have (4) reporting to credit just reach out to a bigger bank/lender. 

The appraisal seems wildly inaccurate in my opinion, ALL 6 of the comps were 13+ blocks farther away towards 82nd Ave, a sketchy area, NONE were in the other direction, Woodstock, of higher value.

Looking for an agent that is used to working with investors, knows the neighborhoods well, where development happens, the good and the bad blocks, the rents I could get, and most importantly is available and can move quick on a newly listed property (already missed a few properties because of that). 

Particularly on the block this property is currently located. 

Blocking tenants cars, chatting it up in the driveway, slamming van doors, just sort of growing out of hand.

Newer and newer requirements are becoming mandatory slowly in design be it high energy efficiency, material which gives more light-air but blocks noise pollution, unhindered connectivity, better insulation, common areas designed for privacy.Which trends you think will be in future of construction specially in term of Design phase and Materials which will allow designers and developers to deliver future requirements.