Indoor climbing is a great workout, but the thing that makes a workout most effective is if it's fun.
If you're on the wall non-stop for hours at a time, you're going to be keeping your heart rate up; if you're motivated to learn proper technique, you'll be using your stomach and legs as much as your arms, and improving your flexibility; and if you're male, you won't be able to help yourself and you'll be getting a big upper-body workout too. But if climbing is a chore and you take five-minute rests between two-minute climbing routes, you'll get little more benefit than if you installed a pull-up bar at home.
> I have not really considered rock climbing since it looks pretty difficult and very technical.
Climbing in a gym is rather different than climbing on real rock. For many people, gym climbing feels safe and fun, and it's a good way to get started. Some never feel the urge to climb outside. For others, the gym is a poor substitute for the real thing.
>Would this be beneficial to a beginner?
Beginner what? If your goal is to walk up Mt Washington, you don't need to know how to climb on rock. If your goal is to experience "the freedom of the hills", then eventually you will find yourself on terrain where rock-climbing experience is helpful. It's not urgent. When you start feeling that fear of heights, you'll be ready to decide whether you want to learn the skills you need to continue.
>2) Is there a workout for getting the most out of these facilities or is it just jump on and see if you can make it to the top?
I'm a big believer in jumping on and figuring things out. If it's fun, it's worth it; if it's not, find something else to do with your time. However, there is a lot of technique that goes with rock-climbing, not to mention a lot of safety issues. I recommend starting with an intro class - this will cover basic safety and introduce you to potential climbing partners. If you enjoy that, ask about a technique class. Better to take that class fairly soon than to acquire bad habits.
3) It looks like these walls would be beneficial for balance and strength but if it is a very narrow benefit for mainly rock climbing, then I'm not sure it would be worth the expense.
As I said above, you can get balance, strength, flexibility, and endurance - if you're having fun. For mountain fitness, you also need running and/or stair climbing, but it's great to have two totally different types of workout that you can alternate.