Alright. So what you actually really want is having your whole network managed by OpenWrt with your custom config. But sure you need to start somewhere. So I think you are doing kind of good so far.
Regarding ipv6 unfortunately the whole internet is not at the point yet where using ipv6 only is sufficient. But I suggest you have a look into it and try to at least set up a dual stack config at home so that your devices get a global ipv6 address and are able to use the internet (might be difficult behind an ISP router though...)
Have a look at this. If you cant do this it might be due to you being new in the forum.