It's scared of you while inside of it's cage because it thinks of you as a predator. Birds, like almost all animals, have to build trust with you. While as owners we'd like this to be a fast process, building trust with bird can be a time consuming effort. The key is patience, patience, patience.
The first thing I'd do if I were you is approach the cage while the bird's calm and gently talk to it. IRNs are flock birds and enjoy being sociable. Hearing the sound of your voice will most likely calm the bird down. Simply talking to our feathered friends is the start of the bonding process. Don't run up to the cage, make quick jerky movements while talking to your bird, or anything else that would otherwise startle or frighten it.
Once your bird is no longer afraid of you approaching the cage, you can move on to the next step. The next step involves you placing your hand inside the cage so the bird can acknowledge that your hand is not something that's going to harm them. While your hand is inside the cage, DO NOT try to poke at the bird, corner it, or anything along those lines. Just let your hand rest so your bird can see it's not a threat to itself or its environment. Repeat this step a few times a day for a few minutes at a time but don't overdo it. Too much and it could stress your bird out. Also, you should be the only one doing these first two steps. Once you have formed a close bond with it, then you can introduce your bird to other members of the family. Doing so will guarantee a much easier transition from one family member to the next. Positive results from these two steps can take time. There's really no time table on when you'll achieve results. It can take a day, a few weeks, or a couple of years, dependent upon on how much time you put into it.
Once your bird is no longer afraid of you approaching the cage or your hands, you can then easily teach it to come out of its cage, perch atop your finger, and whatever else you'd like it to do. Patience is your friend. They key is diligence and putting the time in to properly bond with your bird. If it's not bonded with you, the chances of you getting it to do what you want are very slim. Would you do anything a stranger told you to do with a simple command? No, probably not.
As for clipping its wings, that's your own personal choice. You don't HAVE to clip its wings in order for it to come out of its cage. Most owners clip the flight feathers because if you're constantly trying to catch the bird, training it is going to be near impossible. Another reason for wing clipping is that birds that are flighted are at a much greater risk of an accident. All it takes is one hard crash into a wall, window, whatever, and your bird can break a limb, injure a blood feather, or worst of all, its neck. Birds that are young or inexperienced fliers are at greater risk. I personally choose not to clip any of my birds wings, but again, its my personal preference. I don't think its a cruel practice really, I just think its a bit unnatural. Birds have feathers for a reason, to fly!
Anywho, let me know how the training goes.
what I would love to know how to do is how to actually get her out of her cage when we open it. And how to get her back in? What pointers can anyone advise in that regard? I can easily open the door but she won't come out...