#1 - Beer does not go bad when it is on CO2, when you get a keg from the liquor store, you pump in oxygen and that is when it goes bad. This lasts for months.
#2 - I'm a home brewer. Got a chest freezer with a temp controller and built a tower on top with 5 taps. Use 5 gallon ball lock kegs that were previously used for soda syrup in the old days. Search beer keezer and you will see this is very common setup for home brewers. Thankfully we are having a party next week because I have a ton and am brewing more tomorrow.