For what it's worth:
1 - No. Correct information given so far, but the peltier relies on a heat exchange... if the air isn't moving it won't work efficiently, or possibly at all.
2 - no goo here, strange one...
3 - Only sounds in the two units I have personally used come from the fans. the peltier itself may "hum" somewhat, but there aren't really moving parts so to speak.
If you have the option to replace the "unit" rather than the peltier alone, I would reccommed it if its available. For 35 bux it's a reasonable deal and will take the tricky (not that tricky though) parts out of the swap.
4 - There are brothers using active humidification in their wineadors, but keep in mind that it only humidifies, not dehumidifies, and with temp eratures tising if the peltier fails, or if the hydra goes nuts you can have issues if you are using that sort of setup. I am with Justin on this one, your passive humidification systems are so clean and tight it makes little sense to spend the money for more moving parts and possible points of failure.
5 - There are brothers who swear by various bead placement strategies. "Mounting" the beads is an interesting approach... I can see how you might get to use more real estate inside the cooler that way, but it also seems like a bunch of work. For me... I have a tray at the bottom of the cooler full of beads, and a small stocking with beads in my four drawers. Often the wasted space in a wineador is at the top, and at the bottom... so these seem like natural places to put the beads and to forget about them.
As you can see, preference varies... but lots of answers could be the right answer for you.
Enjoy.
