I understand your problem but you probably also understand that enabling people to download apps directly to their pc's would also enable them to put the apps on multiple phones. Furthermore, it would create difficulties in terms of distributing updates.
If your request is legitimate and you want to be legal about it, your best option would be to contact the developer of a particular app (which you can determine by logging into appbrain.com or other sites) and explain your situation to them.
False.
Ever heard of a thing called iTunes?
Furthermore, it's already possible to pirate Android .apk's without any sort of central source. I think a central program made/distributed by Google with the OP idea is a perfectly fine idea. They would just need to start encrypting .apk's with DRM (yuck, I just threw up in my mouth) so the average user can't go to a folder and swipe them.