I am currently running firmware openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-factory_20130519b.
1. Is this the most up to date / stable firmware version?
I run ckolivas' 20130703 release, and find it to be more stable:
http://ck.kolivas.org/apps/cgminer/avalon/20130703/It has proper fan control too.