1) Allow it to be restricted to a small number of calling IPs (Ex. I want logs for my sites, but I don't want some random person getting the source if he triggers an error). This could be done just by checking a text file with a list of IPs in it or such. (I'm actually not sure if you have this implemented or not, I haven't had a chance to use it yet)

It's not designed for use on live sites, instead for development only. However there are some features built in to help.

For example you can run it from your php.ini file, allowing you to keep it out of projects. That way when you deploy your site, PHP Error stays on your dev machine. It also only runs if display_errors is on, and you can disable it in production. Information on setting it up from outside your projects can be found here, and the php.ini options can be seen here.

Personally I favour that to IP filtering, as with most ISPs your IP changes on a regular basis. It also means if it's disabled for you, then it's disabled for everyone; there is no maybe middle ground.

2) Make your license a bit more prominent, it was a bit hard to track down.

Noted, I'll put the license into it's own file and check it in.