As concerning the warranty, it seems that a clause relating to software under the Warranty Limitations section (Wii Operations Manual, System Setup, p. 36) may relate to the Homebrew Channel as it would be considered "software".
That's too bad if that is the case, but I do understand why. they shouldn't have to be responsible for free repairs on a system which was running non-authorized software. So, I believe this answers question #2 above.
Still, out of curiosity, does anyone here use the Homebrew Channel? If so, how is it (i.e. stability, functionality, etc)?
Thanks for any input.;