rkhunter log

[Luddite Savant]

I've just installed rkhunter & run it (under ubuntu 12.10). All looks to be ok apart from a few possible issues I'll list below.
Reason I'm posting it I ran rkhunter in terminal & got its output, but it is saving the log to /var/log/rkhunter.log
When I try to open this (graphically) in a text editor I get the message:

Could not open the file /var/log/rkhunter.log.
You do not have the permissions necessary to open the file.

Can someone let me know how I can set the permissions on the created log file so that I'm able to access the log report?

Also in the results from rkhunter I got

/usr/bin/unhide.rb [ Warning ]

I gather from other posts this is nothing to worry about, if so how do I whitelist it so it doesn't come up in future?

Also I got:

Performing filesystem checks
Checking /dev for suspicious file types [ Warning ]
Checking for hidden files and directories [ Warning ]

Is this anything to be concerned about?

Thanks