best way is a mini pc you can put an open source OS on
then you totally control it. they can be found cheap used and are usually upgradable
they are thrown out by schools and buisnesses all the time. it does not have to be very powerful by pc standards
it can also be your first home server if youre interested
no, not true you can put whatever you want on it. ours boots into a nice tv like ui and they open stremio with a remote and thats it
its up to you to make it nice and easy
the user experience is not radically different from a corporate experience except its faster and without ads or spying