The LOI should never include:
Binding closing obligations. Again, with the exceptions mentioned, the terms of the LOI should be nonbinding.
Breakup fees payable by the buyer. The buyer is never monetarily responsible for backing away.
Earnest money deposits. These are generally never asked for or included, although they are used very, very rarely in the right set of circumstances (e.g., big buyer, small prospect, a first-time seller who ...