I don't have experience with the NUC for my own homelab and kubernetes, but the main things I will say with any kubernetes is the RAM. I have 4 servers on VMware (just to get experience there) and then have Rancher (like Openshift) across them (both a management server and then a 3 VM cluster). Every resource is important, but the RAM is what was eaten up before anything else for me. I have Lenovo Tiny m910q (x 4) with 64GB and that allows me a full on cluster and then some with other VMs too.
Sounds like you made a good choice going with a NUC and 64GB ram. You just may find you want to add another or two depending how much you go beyond just experimenting with k8s and using it to host most of your homelab services.
You still can. Just block threads.net instance in things like Mastodon and Lemmy.
Your data is public in fediverse. They can scrape even right as we speak.
I would need someone to confirm this, but I have heard that if you block, then it prevents their instance from scraping your data because they shouldn't receive your content if they are blocked, but it doesn't change the public data being available by other means anyways.
Follow hashtags and communities that are your interest. Block users and/or instances you would rather not see or be part of. Also, you can find an instance that fits your values that is already blocking instances you disagree with.
I am mostly indifferent of Threads joining at this time, but those that are not in favor, there are options.