Hmm, why can't you use that one?
In my opinion it would be the best way...
Otherwise you'd have to find You are not allowed to see php code. in your index.php (line 44) and change the code that follows...
Change the following:
You are not allowed to see php code.to
You are not allowed to see php code.and add the Hide plugin too.
You'll have the same effect as you have with deactivating it in the groups - with one exception!
The online.php (Complete online list) will still be accessible for guests.
Find in line 24:
You are not allowed to see php code.replace with:
You are not allowed to see php code.
Now your online list should be protected.
I guess this can also be achieved without changing the core files but this is the easiest way if you can't / don't want to use the guest group permissions.
To your final question:
I'm still developing new plugins, in fact I just started.
At the moment I'm quite busy with other stuff like school but I'll have more time soon (hollidays) and then there will be a wave of new plugins
Kind regards
Lennart Sauter