I see it very simple, if you're participating in loyalty and discounts program, then cgtrader is in control of your prices, if you don't participate, no matter price offer status, then you're in full control of your prices. I quit those discount programs 3 months ago and didn't look back once. I think they worked for me as a seller at the beginning, but then cgtrader started to overuse it to ridiculous point and i felt that i don't want to ride that wave anymore. I wasn't sure if my decision won't hurt my sales badly, but luckily it didn't. It's still sad to see how majority of sellers here fights over each other who will offer bigger discounts or will set lowest price for their work, but i try not to react to things over which i have no control.
As for price offers, i like that option, because i can communicate directly with customer and from case to case decide if i want to give the discount and what size would it be. Discounts doesn't happen often and not every of them turns in to sale, so i feel perfectly fine with them. Funny fact with price offers, that no single offer that i've denied, turned out in to sale. I think that means that offers are used mainly by those that aren't in dire need of the model.
Anyway, if you're in chase after every single sale, then you should participate in sales and loyalties programs and turn price offers on. On the other hand, if you want to earn from each sale more, then turn everything off and be happy. However, if you don't know what you want, then i suggest to do experiment - sell on month with discounts and another one without and try to see what you like more :]