Does anybody know where to find the comprehensive OpenVPN setup guide? It looks like it was taken down? Or should I follow the old streamlined setup guide?
One of the authors of that page "had a bit of a hissy fit" and removed it, from what I understand.
While that page was full of information, it was often very difficult to understand and mixed with personal opinion without clear disclaimers. There are pages at that replaced it some time ago for OpenVPN configuration at https://openwrt.org/docs/guide-user/services/vpn/openvpn/basic
What, in particular, do you need some assistance in configuring?
If it's something a little out of the ordinary, in addition to asking here, here's how you might be able to find the information you need from primary sources.
Was reading that OpenSSL would give a lot better security than setting things up through Easy-RSA, so was wondering how to set things up correctly.
Yes, there are ways to create a CA and certificates that are more challenging to "break" than what easy-rsa sets up, but https://openvpn.net/community-resources/how-to/ does point to easy-rsa in its setup instructions.
Reading that page, it states
On *NIX platforms you should look into using easy-rsa 3
instead [of easy-rsa2 or prior]; refer to its own documentation for details.
You can always change to "more secure" certificates if your research leads you to believe that the ones generated by easy-rsa are not secure enough for your needs or desires. Getting something decent up and running is often a great first step for getting something even better running later.
Here's one (of many) references on how to generate a CA and self-signed certificates; https://www.freebsd.org/doc/handbook/openssl.html