Hello Gent,
Don't worry, I figured it out and it was partly me being a doofus
The permissions on my Project64 folder mean that unless I run PJ64 as an Administrator then it won't be able to create the ini file. So pressing 'Save' doesn't do anything in this instance.
As soon as I ran it as an Administrator, and configured the plugin, tr64_ogl.ini appeared!
Had a look at that file and I see what you mean, think it would definitely be better with the changes you are suggesting - will have a look at your sample ini too.
Cheers,
S.