1. Yes it can download full games.
2. No, you will need to provide a ticket for it to be able to be installed. You can find them on that ticket dataBase site.
Is wuphaxx a cfw. OK so here the deal I downloaded wii u usb helper download duck hunt for example and it fails. The way I modded my wii was with wuphax. I do have loadiine and wup installer. The viiwii which is hacked but not sure if my wiiU menu is because the virtual console games never work
Something like funkiiu or that wii u usb helper program might be more suited to your needs.
They can download and include needed tickets used for install including patching of dlc.