If you can't get the piece out, you can simple fold the top into the hole and patch over it. if you want to re-install the rail into the deck, you may have to have new holes core drilled into the concrete. 

Install a crawlspace well or window well/ventcover, depending on size of vent.

It is also clear some of the work done on the house is shoddy (forgot to pain ceiling under the cabinets while they were being replaced, didn't complete the tiling of the floor up to the wall, painted windows shut with sloppy paint all over windows, supposedly fixed termite damage- but placed a beam next to a damaged beam in one corner of the house only). 

My next project is to install laminate in the hallway and master bedroom and cover up the paper bag floor.

Then, Installed separate meters.

It's a little over half acre..Front 120, left side 170, right side 192 back 132..Seller seems motivated..The utilities are in place, but would need to install septic system...Any insight or questions of concern??

New paint, laminate floors, new cabinets, granite, new tile and finished the attick space to create a 3rd bedroom/bonus room.

If the house does not have a working automatic sprinkler system which can be set to water automatically, you will need to either install one or at the very lease have soaker hoses put around the perimeter of the house and set up with an automatic timer. 

If any odor/urine lingers in surfaces, any coating/painting/repairing work you do may only mask the odor ...temporarily.I'v already replaced all flooring with porcelain tile ( on slab that was probably not cleaned good enough), Kilz ceilings and wall surfaces, replaced windows and all base boards and odor still lingers. 

If it cannot be repaired as told by multiple trusted asphalt driveway installers I strongly suggest ripping it out and installing a new one that is up to local code and ordinances.