@Ulli: those are older templates... I changed the names in a later version. But no worries, they are still okay ;-)

Hmm, what am I doing wrong? Or is it just because of that bloody mac? :/
these are the only presets I can choose, am I right?

You could try using the PRO templates.

But it can't be that everyone else gets nice results whereas mine look like I recorded that with my smartphone, can it? I'm using a 27" iMac with enough power... something's wrong.

Perhaps "everybody" uses the protemplates? ;-)
Have you tried other templates? eg with 29,97fps? Same results?

Try the pro templates - 10/12€ and you get videos up to 100Mbit/s from LR.

Well, I don't know actually, yes. ;-) still seems a bit weird to me. I'll see. I've tried 25fps I think and the result was the same.