only enchants that dont require a level work on heirlooms as they are classed as level 1 items
so... like fiery and icy will work but mongoose wont as that is 35+
Enchants have a built in minimum item level now. blizzard did this to keep people from enchanting wrath enchants on items to twink with. It was put in with the patch that broke twinking with separate bg's for the experience locked/ experience gain in Bg's to make it so eventually you will level out of a bracket.
A good enchant for a BoA wielding rogue is lifestealing, or crusader. Both heal I'm not into rogues so I don't know which one is best. I know for warriors and paladins crusader is best for the strength proc. You can also do the 15 agil to onehanders, or the elemental enchants (fiery, icey) should you want.
It's Penguin Heaven, Dave. It's anywhere you want it to be.