Hi Landen,
I'll try to help you as good as I can
1) Absolutely yes!
2) Do you have a v3 or v4 sound board? The v3 has only one sound bank whereas the v4 has up to 8. To change the font on a v3 board, you'll have to download and unzip the sound fonts first (found on the Ultrasabers store for free) and then add/replace the font files with the appropiate ones, i.e. only replace the power on file with another power on or a clash/impact only with another clash/impact file. On a v4, you should be able to access all banks through the "Banks Selection" section and then select the different font parts (Boot Sound etc.).
3) I think that's only possible via the "Format Memory" function, but I'm not sure because I don't own a v4 sound board.
4) Maybe some of the v4 reviews cover that, if you're not happy with the US video.
5) You can only restore the original sensor settings, but not the sound fonts. These can only be restored via uploading them to the board again, but there's no sound font backup implemented in the board I think.
Hope that helps a bit. If not, please tell us so that someone else can chime in