Hope this is some help
#1 - Yes usualy 1 or 2 $ per bag. If I have say 4 bags, I ususaly tip $5.00
#2 - Same answer as 1
#3 - Room steward, waiter, assistamt waiter tipping is done on the last night. Celebrity now will let you place tips on your on board account and you don't have to worry about it again. They give you a card to hand to your waiter, housboy etc.
Room service I usualy give them a couple of bucks depending on how much they bring. Just coffee, I give them $1.00
Inclusives:
You pay for soda, alcohol etc as well as they charge your onboard accound for the specialty restaurant. No further tipping is required for that. You do pay for expresso etc. but juice is provide at meals free I think (I don't drink it so I'm not sure.)
Use of facilities is free except spa treatments.
Dressing up:
Jeans and Polo shirts are never acceptable for dinner in the main dinning room. Breakfast & lunch they are OK.
Celebrity folks do tend to dress more for dinner than say Carnival and some others.
If you don't want to dress then the alternative casual dinning spot is available for a small charge.
Hope this helps.
Russ