Beer question #1.
Why does beer taste especially yummy right after you brush your teeth?
It doesn't. You're fucking gross.
Beer question #2.
Why do I seem to get worse sunburns while drinking vs. not drinking?
Any activity is more fun when drinking, thus you spend more time outside, thus resulting in more sunburn.
Beer question #3.
What determines the darkness of beer?
Dark beer is dark because it's made with dark malts (dark grains), and the malts are dark because after malting they have been dried with strong heat, which has burned the malt to some degrees.