Performance cars need performance seats.... and reclining seats just dont perform.
The 5-point harness without the roll bar is asking for trouble. That is if you use them.
If a 4 point harness is installed without the shoulder straps fastened directly to the rear (meaning if they go below your shoulders when secured) it increases risk of breaking your collarbone.
More so where you stay in place in the seat and harness, you can have your head crushed in a roll over without a roll bar. In the same sense with a roll bar your head could bounce off the bar in a collision. It's a no win situation.