From what I've read, the "T" pose is for some programs to get a zero pose, as when you load a poser character. I've used BVH quite a lot lately and I do the following:

Load figure and apply the BVH file. on frame one I adjust the hip Y trans to the required height then I go to the graph and select all of the other key frames and bring them up or down as a group to match up with the first. If the shoulder is dropped to 30 and 14 looks best I get all the other keyframes and align them with the good one. In the case of the hip or shoulder there might be some subtle up-down you want to preserve to make a walk look good. In rotations I might see a joint rotated to 700 degrees (don't try that at home) I adjust one keyframe at the graph maximum untill it looks good and drop the others to match. BVH files almost always need some tweaking but this method works well. I don't remember where I picked this up at but somebody smarter did it first. Others will use the body rather than the hip to move stuff around but that won't save back because BVH does not recognize it. Once everything is set right you can save it out as a BVH export or a pose file. 
The "santa" file you guys found looks like a treasure, I'll be busy for a while I think.