Hehe... you can do that? I've just been "following instructions" based on the tutorials.
You may use any of the multiple controls that are stored (and can be customized) in the Controls dialog. Check it out.
Quick questions --- how come there is no tutorial for the Challenger?
Technically the Challenger isn't yet considered completely done. There's a very real danger that tutorials could become obsolete or misleading with later changes. The Chally as it is represents our best estimate based on what's publicly available information (which is very little). We hope that with a bit of feedback from UK tankers we can further improve our work.
And how do you get the "outside view" again when playing?
which view is "best" or ideal for just moving from A to B?
It's probably a matter of personal preference. I'd say, any position but the gunner or squad leader (for those IFVs that have this position modeled) is equally suitable. Of course they all offer their own distinct advantages and drawbacks. Try the different positions, I'm sure you'll develop a sense of what works best for you. If you can get yourself accustomed to using the commander's position, that would probably be best for multiplayer games where, if you don't occupy the commander's place, another player could jump into it and take control.
I'm not sure I can do a very good job as a TC,
The only chance to learn it is by doing it.
but I don't want to be in the gunner view the whole time,
That's a good idea, if you do it for the right reasons (=lack of situational awareness, tunnel vision, target fixation). However,
hence asking about the external view so I can admire my ride before it's blown to bits.
Even though I suspect that it was meant tongue in cheek, this is a somewhat popular mistake of some. It could be an indicator that your attention is focused on your own vehicle, when you should spend most of your attention on the anticipation of emerging threats, and being on the lookout for them. This is probably the prime directive for a tank commander (and platoon leader) in combat - being focused on what the enemy might do next, where it might make its appearance in your field of view and your area of responsibility, what the best terrain features are to help you to maneuver to the place where you need to be, to mask your movement, and your presence.
Looking at your own tank won't help you a single bit with any of these tasks.