If you're not using it to make money it's never not OK. I can't see it as theft. It's just a different method of obtaining the same thing that doesn't harm anyone.
Not only are those making this choice unlikely to pay anyways, but all the regular people who worked creating it already got paid so nobody can say "oh the film crew, VFX artists etc will be out of a job". No they already did their job and got paid. The investors maybe want more money but they aren't hurting for it, I don't feel anything for them.
If you mean accessing them from within your LAN while your internet is down then no it won't work.
What you should be doing is either split horizon DNS (LAN resolves local IPs, public resolves public IPs) or use different DNS hostnames internally, for example media.local.yourdomain.com
You then set up a reverse proxy in your LAN and point everything to that, use a let's encrypt wildcard cert using the DNS challenge method so you can get *.yourdomain.com protected with a single cert. Since you use cloudflare you can use the cloudflare API plugin with certbot, it'll automate everything for the DNS challenge and no need to keep opening ports or configuring http/https challenges every couple of months.