Neighbors house just listed for 380k and one block over a house just listed for 417k.

I lived 2 blocks away from one, once.

Buy a lot of these if you renovate plastered houses.Learn how to use a block plane to shave down wooden doors.Don't ignore hearing and respiratory PPE.

Ohio is a judicial foreclosure state and the property is up for its first time on the block.   

Block off an early-to-mid week couple of days for the AC.

You do need to use anti-spam tech to not hey blocked though.

Can people intentionally play games to put liens on property to block the tax deed buyer to get clear title?

Since he was 6 months late on the loan, I had urgent needs for the loan and wanted a wire for many reasons (my bank- bank of America puts holds on all large checks, so I am blocked from access to it for a week) and I didn't trust him with my wire information as he told me point blank "I'm not going to give you that information" when I asked who the closing attorney was. 

What's the best way to block this thing up so they can't come in?

Once or twice a year, a week should be blocked off the property, and maintenance included touch up painting should be done.