You can play scrubbed games from usb - I understand that a "scrubbed" game is a game that has be "scrubbed" of garbage data that was intended to fill a Wii disc. Can you play a "scrubbed" Wii game from an external or does the game have to be in an ISO or disc image format to play?
You can scrub it - Is there anyway to compress game size to save space on the external without the loss of game integrity or having game-play issues.
Your choice, usbloader gx, cfg usbloader, wiiflow. Try them all and take your pick. You probably only need one. - I understand that there are USB loaders out there, dozens and as with most software only a select few are worth mentioning. Is there a one-all-be-all USB loader that will accomplish everything that I require or will I need multiple? Is having multiple installed going to create issues in the future?
Yes, 4.1 is fine. - Can all of this be accomplished with the current 4.1u software I have installed?
The wii has no internal dive, external hdd is used. There are methods of installing an hdd internal by removing dvd, but not much point. - Is it possible to replace the internal hard drive with say a 2TB hard drive? Is there any benefit from replacing with a SSD if possible?
You can transfer files over the network from one hdd to the wii hdd, but there is not method to load wii games from a network cloud. Homebrew, movies and such can be loaded from the network, but wii games need to be local. - I have a 3TB external plugged into my router, is there a way to store games on this external and reach it from the Wii via Ethernet/USB adapter or is an external required to be plugged into the Wii directly?
There is a list of compatible drives on this site, in the recommended guides I think. Have a look at that before you make buy an hdd. - I have not yet bought an external pending some of the answers to my questions about, particularly about scrubbed Wii games, but is there a brand that works better than others (I prefer WD over anything), is there size limitations to the drive, does it need to have an AC adapter or can it be powered via USB, with the PS3 the drive had to be formatted and folders in particular order otherwise it would not read correctly, is the same with the Wii?