Welcome to Cruise-Chat.
1. Don't know for sure but don't think so.
2. You won't need to hire them. On formal nights they're everywhere. Just pick the backgrounds you want to stand line for pics at and the next day they'll have proofs for you to choose from at the photo studio. They're also outside the ship at many ports and at the check-in area, in the dining room. You'll have no problem buying all the photos you want.
3. You can book excursions as soon as your final payment due date arrives and your booking is paid in full. Don't go crazy, you'll need some down time or you'll need a vacation from your vacation. I plan almost nothing in advance. Most cruisers do plan and book some early, especially many who don't cruise a lot. They're afraid they'll miss out on something. Many of those folks are regretting that decision this week because many itins have changed due to the storm. That means cancelling what they booked and scrambling for replacements on the fly. If the weather is ugly when you get there, you're in the same situation. If you meet a cool couple at your dinner table and want to hang out with them, better hope they booked the same things you did. There are other reasons I don't plan very far ahead, I just may not feel like it when we get to that port. You may be a detail oriented person and doing it my way would make you nuts. If so, book 'em.
First step will be final payment. Then go to www.royalcaribbean.com
Across the top of the screen there will be a row of tabs. The center tab says "Before You Board". Put your cursor over it and a drop down menu will appear. First click on "Online Check-in" Do that and you'll be able at the end to print out a "Set Sail Pass". Don't lose it, it's your boarding pass. Then repeat the process and one of the tabs say "Shop for Shore Excursions". After you've registered, these will be specific to your cruise not a generic list of possible options.
Have a great time!