I noticed my PHP .ini file is the one from PHP4 even though I am running PHP 5 now.

When changing session.cookie_httponly and session.cookie_secure I noticed they weren't there so am wondering if there are other declarations that might be missing.

I'm especially wondering about security but is there anything else that is important?

Differences

You can find all old php.ini recommendations online, for example the one from PHP 4.4 on Github.

You also can find the new recommendations online, for example the one for PHP 5.3 on Github.

You can diff those with any tool (for example this site provides an online differ), which should give you a good overview on what changed in the last years.

What I would do

Please notice that actually all PHP distributions contain the php.ini-recommended or php.ini-production. You can just pick this file and fit it to your needs, which should result in a much better configuration file than you updating your old file manually.