I am also wondering how to structure the lease the best for easiest way to get property back if default.  

Also, if I were to owner finance the land, any improvements they made would stay if they were to default.  

After talking it over more with my husband we decided lease optioning would be the safer route for us to go, so that if they default we are evicting vs foreclosing.

Usually there are lots of terms inside the existing open end note which deal with freezing of draws, repayment and default.  

I'll bet you could talk to a syndicator type all day and never be informed of the risks, collateralization specifically or the outcome of default, it's simply counter to the sales pitch. 

Tax default?

You can place that provision in the contract for purchase and sale.For earnest money it is key that the language is written in a away that the EM - IS NOT interpleaded into a court of law if both parties cannot agree.If the buyer can demonstrate that the seller is in default or that the buyer has the right to cancel then the sellers consent will not be needed.It's important to have that in there because I have seen sellers or attorneys do a ransom where they say your 50,000 earnest money we will dispute and then title will have to interplead into court.

I've spent the past 6 years as an Asset Manager in the default sector liquidating REO's for the banks by rehabbing them for the retail market and the auction market (primarily Auction.com).

No, you can't refuse payment on the second, state law will dictate late fees and default procedures, no attorney wrote that I'll bet.

The lease generally states if the tenant doesn't renew the option periods then the ground owner gets the building by default.