1) A stand-alone Patch binary doesn't have to be the whole thing, just the difference. Most stand-alone game patches are just bundled into a windows installer anyway.
2) Not really; It could be a VPS host with some bandwidth, an EC2 instance or even Dropbox. I'd be inclined to run a torrent as well since I bet a majority of the people here know how to use it. As for being unprofessional, this is for an Alpha/Beta version. The software is going to be buggy anyway so I doubt reputation is based on the download method. They are going to make it all nice via Steam when it goes Gold anyway as I understand it.
Just seems to be there are more disadvantages and hurdles than there are advantages.