Depending on your level of paranioia. First, you don’t expose your containers, but their port(s).

With a reverse proxy, you will likely expose only 1 port, 443, no matter how many apps/containers/ports it will be pointing internally. For this, having a proper dns setup will be key, and a service like cloudflare dns (not tunnel), which additionally you can proxy your proxy. Also, you will need certificates (letsencrypt) for your traffic to be encrypted. Here, everybody will potentially have access to your services.

Another option is a zero trust tunnel, but as you had seen streaming may break tos. It will be likely enforced if you stream a lot, but I seriously doubt you’ll get any problem by having sporadic one or two users.

Tailscale, you need to add all the devices you need to access your services into the mesh, and you’ll need to re-authenticate every one again every few months.

Setting up a VPN (selfhosted) will require your devices to sign into it when accessing your services, and it seems to me the best approach as this way you will nave the most control over your setting.

Don’t forget to mention that, for this to work, your ISP should provide you with public IP, because if on CGNAT you will have to go with something like tunnels or tailscale.

You can place both containers within the same gluetun network, and make gluetun expose that containers ports

None that you know about

I have some thermo regulated valves that require 1.5v as well, so for those I decided to go with regular alcaline batteries. Those are still above 80% charge after 1 year of usage, that is why I decided not going with rechargeables for those trvs

But there are 1.5v rechargeable AA batteries out there.