IRSSI Keys on a MacBook Pro

At $newjob I'm using a late 2011 MacBook Pro, so I've had to relearn some keys for IRSSI. The important ones to me are:

• fn + up arrow / down arrow: for viewing the backscroll (page up / page down)
• Setting an option key to "+esc" under iTerm2 so I can hold down the key and use left and right arrows to move through open windows.