About 20-30 at any given time. I expect to be able to see the list of domains I own, when they expire, and if auto-renew is on or off from one convenient panel.

Also "just silently auto-renews" is not an okay behavior for me either. Even when I have auto-renew on, GoDaddy sends me email notices around renewal time for any of my domains. I like to manually renew them a bit early to ensure there's no problems with payment processing. Obviously I have like a year until any of my Cloudflare-held domains renew, but if I don't get email notices in advance, I will likely look at transferring them away. Proper notice of account/billing activity is a must for trustworthy service.

For one, my host auto-configures a lot of features on the DNS for my domains. Cloudflare imports it, obviously, when I transfer over, but if my host changes something, Cloudflare isn't going to get it, and I don't even have the option to change my name server provider even temporarily for troubleshooting purposes. That's a big flaw, and Cloudflare will need to fix it to keep me.

I don't have any .io domains, but my understanding is Cloudflare keeps literally nothing for any of their domains, so presumably Namecheap was able to cut a better deal with the registry.