In the majority of cases, a separate NDA (aka confidentiality agreement [CA]) will have been executed between the parties during the initial discussion stage, prior to the drafting of a LOI. An NDA imposes binding obligations of confidentiality that will survive the non_binding letter of intent.
Of course all of these items are important, and these are the details you should be thinking about before you make the Offer to Purchase. Why? More than likely you and the seller will not agree on everything. That is to be expected, so many of the items above, as well as other items, will need to be discussed and worked out. So what should you do?