1. Beer is sold in Aluminum cans and maybe glass bottles as well. I like the aluminum cans because it stays nice and cold for a bit.
2. I haven't seen diet Mountain Dew on the ships yet, sorry
3. I'm not sure about the flavoured creamers but they have flavoured syrups for coffee drinks as well as almond milk
4. The drink of the day will be advertised the night before in the cruise compass. The only deals i've really seen is the odd drink card - 10 drinks for $79 - but not on every cruise. I think it's just offered when drink sales are lower for that cruise, not quite sure. I did a b2b once last year and it was offered the first week and not the second. Also, it's not offered until the last few days of a cruise. There is usually a deal on a bucket of beer though.