The lease survives the sale as Ned stated.

My biggest issue, as Ned already mentioned, is finding quality vendors that are responsive to my maintenance requests.

As @Ned Carey pointed out, we were all new at some point.

This is to avoid being flagged by the IRS computer for mismatch.Keep good paper trail in case you have to defend this deduction, as @Ned Carey pointed out.

As Ned said, take a look at what is common for your area.

., as @Ned Carey said you can't 1031 a note. 

As Ned said, it depends on the demand for commercial space in your area.  

As Ned Carey & Joel Owens have indicated, I would make the removal of the tank(s) e negotiating factor in the deal: either the Vender removes the tanks and handles all remediation {you will want proof it was done professionally and there is no soil contamination (or non remaining)} or you handle it but reduce the offer accordingly.

As Ned suggested, buyers are easy - get a good deal and you will have plenty coming to you.

But as Ned Carey stated, every state has unique laws that you must read and thoroughly understand every word.