I feel like lifts are a snowboarder's worst nightmare! I'm not sure why supporting your board hurt your ankle... maybe try a lighter board?
Anyway, I feel like I got the lift stuff down, but I've only been out 5 days, so watch me screw it all up next time!
This is what I do (and a lot of it is what Consonantal just said):
I actually sit a bit sideways on the lift chair when I get on and point my board straight, keeping the nose slightly up. This requires that I twist my body/ankle a little bit but seems to work. When getting off, I prepare by sitting kinda sideways again and pointing my board. And I actually put my back foot next to the back binding before I ever get off. After that it's just a matter of sitting up properly and looking straight ahead, that usually gets me off in one piece.
This video explains what I just said, it might help you with that pesky lift:
How to Snowboard: Step 5 - Riding the Chairlift - YouTube
Taking lessons is probably the best choice you can make in the beginning. Since your bf isn't that experienced, he might benefit from one too
And you are surely not alone! I became a master of the faceplant on my second day of riding (and lessons)
Edit: blah, video embedding didn't work for me.