I'm buying tokens back with my own profit, the 30 million tokens I keep from the ICO.
There's not going to be any significant reduction in bankroll, max 10% every 3 months.
Yes I will then be making a profit on the tokens I hold, the ones not being sold plus the ones I buy back, that's pretty normal and how most businesses work.

Remaining token holders have the benefit that their tokens have much more value the longer they hold them. They can choose to never sell them back to me for many years or if the site was to be sold.

There's no dilution going on at all.