Joecru. welcome to cruising. However I have to say I believe you are wrong regarding Carnival ripping you off. I've been on the Glory 5 times and never felt ripped off. If you stayed at a nice resort on land for 7 nights, and ate out 3 squares a day, you would probably be out a lot more than what you were on Carnival.
Re / prices--- I'm just using a coke as an example--I was at P.F.Changs for lunch yesterday with some folks--had a diet coke to drink----it was $2.50.
If I consider a .15 % tip on the coke alone, that would bring the price for the coke to $ 2.87. They're cheaper than that on Carnival.
Most main stream cruise lines operate the same way re / the tipping system If for some reason you dislike the service, you can go to the pursers desk and have the tips removed. By the same token ( and most people do ) you can add to the tips if you feel your server or cabin attendant deserved it.
Again, as I said most lines, RCCL, Princess, Celebrity, etc. all operate basically the same way. I'm sure you'll enjoy cruising --just remember--nothings free!!
Happy sails to you !