Dear Mr. Jones,
You have a fiduciary duty to the non-executives. That essentially means that you have a prudent man standard and cannot get for yourself anything that the non-executives cannot get, for example, I will lease to you if you give me a 1% overriding royalty for myself.
The duty of fiduciary only comes about when the lease is signed. You have no responsibility to the non-executives until you lease the minerals. One item that comes to mind is to ensure that all of the non-executives are paid their share. It used to be that the duty of utmost fair dealing implied that you must lease. In RE Bass, that standard was removed.
There was a time when the executive right was a power (to lease) coupled with an interest (in the minerals). Not so, anymore. The Executive Right stands alone.
http://www.mineralrightsforum.com/profiles/blogs/the-executive-right
The person owning the executive rights (the "executive") does NOT automatically receive the bonuses/rents/royalties associated, it depends upon the exact wording of the instrument of conveyance whereby the executive and his predecessors in title had possession of those executive rights. It was on this issue that one of my former mineral brokers made his only known mistake in my seven-year experience with him, he thought the bonuses/rents/royalties DID automatically go with the executive. The executive DOES have a fiduciary duty to the Non-Executive Mineral Interests (NEMIs), and in some cases is required by the instrument of conveyance in which the executive rights are severed to sign a lease for a base amount. If you're worried about the surface damage "issues," see if the Lessee will include a No Drilling or, preferably, a No Surface Operations clause in the lease. I seriously doubt they will accept that since you have so much acreage, but they might sign two leases with you, one for acreage to which that clause would apply and another one to which it would not apply.