IMO the proposed system has several flaws:
1. By using a selected set of block producers, you inherit what people seem to perceive as the most serious flaw in DPOS: a majority of these control the chain and can squeeze out any attempts at stopping them.
2. For economic reasons, miners spend less money on mining than they can earn by producing blocks. You propose to reward miners with TX fees, but TX fees are very low in all crypto coins. This means the global hash rate will be very low in your chain, which means a determined attacker can easily take control (i. e. >50% of the block producers).
3. By using a separate token for mining and buying into the top block producers you run into the nothing-at-stake problem, or a variant of it. An attacker can mine these tokens over a long time, then spend all of them at once, in order to take over the chain (i. e. buy >50% of the block producer slots).