Pihole Dnscrypt-proxy ipv6 and other Issues

Hello,
I’m new to Truenas and have the following Issues, I did some research but the Documentation isn’t very clear and old forum posts have way more settings then I do.

Pihole DNS ipv6:
The ipv6 address is changing and can’t find a prefix setting in the interface settings.

Dnscypt-proxy from klutchell:
I wanted to install this program like a reguler one but it gave me warnigs, so installed this Docker image, and shell is not working, it says bash not found, log works but it only shows old logs. And when I set it up as the DNS in Pihole it didn’t work. Bind to host network is enabled and the port of the DNS is changed. I tested it with a local Doh server and it worked.

Have to enable ACL on app settings:
I have configured and allowed Apps on the Dataset ACL but it still doesn’t work and I have to enable it a second time in the app settings.

Uncorrectable sector:
I got that error on the boot hard drive, does this mean the hard is broken?

Is a slow system okey:
The system is an old office PC with Athlon Dual Core 5600B and 4gb of RAM, and it’s running with Jellyfin Jdownloader Syncthing and Pihole just fine. So would it be beneficial upgrading beside speed benefits?

Thanks for reading.

4GB is less that the reccomended minimum of 8GB and thats without running any VM/App/Containers

Your athlon is also very very old but i probably less of a problem than the memory