I think you're on the right track with limiting access to the pond for special, invitation only events. Having had experience with operating a campground, I can attest to the "I've paid to play, now get out of my way", mindset of some members of the general public. Time to fill the freezer, with your fish....
On the other hand, if this is to be a commercial, (with an eye towards profitability), enterprise, and you desire a specific clientele, then I think the fishing experience needs to be above and beyond, so to speak. Something not easily found elsewhere.
Perhaps you were intending for this pond to be a test drive of sorts... a way to showcase your fish, and your talents? A way to give your clients a hands on feel for what they could achieve, with a little guidance and expertise.
