mcfam123

It's true. You can order a steak or lobster tail in the main dining room for an additional charge any night, but there are evenings when those items are on the included menu.
 
It's essentially for people that want steak or lobster every/any night

As Matt stated, there is a steak and a lobster option for an extra charge, both of which are from the specialty restaurant, Chops, and clearly marked as such. There will always be a beef entree and an always available steak entree on the included menu. These additional items allow for a higher quality entree without having to dine at the specialty venue.

They'll ask for your cruise card to charge it to your onboard account, so that will be your first clue. In addition, other than the complimentary beverages listed, there will always be a charge with the only exception being complimentary juice at breakfast. If you drink sodas and or a lot of non-alcoholic drinks, you might look into one of the beverage packages.

You may find this blog post about dinner dress codes helpful: http://www.royalcaribbeanblog.com/2014/07/21/first-time-cruisers-the-truth-about-dress-codes

WhiteSoxFan - If you find that you have leftover OBC that you need to use or lose, just go to the casino and get chips at a table for whatever amount you need to spend. Example....if you have $100 of OBC left unused, go to a table at the casino and as for $100 on your seapass. Now, they WILL charge you a 5% "convenience fee" (so there will be a charge on your account for $105) but you can turn right around and get cash for those chips at the cashier's cage if you don't want to use them to gamble. Sure...it will cost you $5 but at least you won't lose the $100 OBC.

Generally speaking, the bare minimum is a collared shirt and long pants.  Suggested dress ranges from casual, to smart/resort casual, to formal, the later of which might include a suit or a tux.  And while jeans were once frowned upon, other than ripped jeans seem acceptable by today's standards.
 
Personally, I no longer pack a suit or a sports coat.  On formal night, I go with a tie, dress shirt, and dress pants only.  Sometimes I'll add a vest.  The only cruise line that I needed a jacket on was Holland America; however, it sounds like coats might be required at the formal restaurant on the Quantum class ships. 

Generally the attire is trending more and more casual.
 
If you want to dress up more you certainly can though.
 
I have increasingly gone with jeans and polo on non-formal nights and slacks and a button down shirt for formal night. If my wife is good with it (which she is), I am not bringing more dressy clothing than I need and Royal doesnt seem to have any opinion on it, so casual is better for me.