I'm not sure I understood this correctly, because if your Mini is asleep it should not be able to download anything.
Launchpad is an application. Speeding it up somehow (such as using renice; by the way, don't do it) isn't going to make your downloads faster.
While you might explore opening up certain ports to possible improve your download speeds from the Mac App Store (TCP Port 80, I think), you're probably not actually experiencing a problem. The Mac App Store will rarely push data to you near the bandwidth maximum of your ISP or local network. Or your ISP might be throttling the speed of data it will transfer from the Mac App Store. So there's likely nothing you can do on your end to improve this performance.