After searching a bit more on Internet, my mistake of making "free minting" does not seem to be so scary after all. Actually, I might be good. I came over this article today, which explains a bit more: https://rarible.medium.com/create-nfts-for-free-on-rarible-com-via-a-new-lazy-minting-feature-91cb4b7c68e6
As they say, this new option should make Rarible more accessible and easy to use and should lower the entry barrier for NFT creators. I especially like what they write: "Once the purchase happens, the NFT will be minted to your wallet and then transferred to the new owner automatically. It’s as simple as that."
As I tested a bit last weak with another wallet, it seemed like the gas fee would be many times higher than the sales revenues (if transferring to another wallet). But I guess one of my misunderstandings is that this gas fee also includes minting. As you can read from the picture above they call it "Minting gas fees". Also when testing today, 2 weeks later, the gas fees are about 4 times lower than when I tested last time. So things look much better today :) So with this in mind, actually the free minting could be a good thing. I like very much the idea to lower the entry costs.
I will pay for the minting cost in my next NFT, just to learn more about the difference. But after today I am much more optimistic about the "Free minting" feature.
Verified account Rarible
Since I am new to the platform, my account is not verified yet. I can understand that people don't want to trade with people who are not verified, so my next step is to get my account verified so people can feel safer. It might take a couple of weeks, and I will make a post when it is verified.