I see you can use ini files efficiently enough. Would it not be more prudent to instead categorize them by channel? It seems that you're categorizing them by nickname, which means the file will have several sections with only one entry.

Structure is as followed:

[#Channel]
Power=10
BluntMasta=9999

Which can be called with a slight modification to that of your own. $readini(users.ini,$chan,$nick) which would return the number or level associated with that nick on the particular channel. As such on channel #Channel I would have an access level of 10 and you would have an access level of 9999.