is the cpu cooler good enough?
Is it worth to go for the bit more expensive gpus?
Are the corsair PSUs bad?
And should I wait for major discount days such as black friday to maybe get it cheaper
The 3700x isn't a hot chip, so the cooler should be fine, you can always upgrade later if it's a problem.
If the gpu is paired with a high end monitor, say a 1440p 144hz, then sure, otherwise the 2070S is ample enough, the encoder doesn't change regardless of the gpu.
Corsair isn't bad, but the CV and CX-m units are meant for lower end systems and have outdated designs and inferior load regulation/ripple.
Black friday...you could wait, save maybe euros 100, but by then the next gen of amd cpu's will be out as well, so it's up to you.