Okay, that pic clears it up. She is ever so slightly calf-kneed (also called back at the knee). That means that her legs are not exactly straight and they bow backward at the knee. If it is a severe bow, it can cause some serious lameness issues due to the added stress on the knee joint and the rest of the leg as well. With hers being so slight as it is, I wouldn't worry about it at all.
It would be cruel to try to pull a two inch wide mane enough to braid normally. A running braid is even hard with such a thick mane. My student decided to roach her haffie's mane and it looks great, IMO. So much tidier and neater. She leaves the forelock alone, though.
I looked at the versatility photos and most, if not all, did not have their manes braided in disciplines where normally mane is braided. Any reason for that?
Its tradition with the haflinger breed to keep a natural mane. The super thick (and many times even double) white mane is one of the pride and joys of the breed. Sometimes you will see them in a lattice braid but that is about it.