Thanks for taking the trouble to answer, englishal.
Yes, I know the principle of Softkeys - they were on my TV and mobile phone long before Garmin introduced the G1000! My specific problem with the SUSP/OBS Softkey is that the very comprehensive notes don't make it clear (not to me, anyhow) under what circumstances they become visible/available; and in particular whether I can call them up at will. Yes, I've noticed that the OBS Softkey can (but doesn't always) appear when using GPS, but it 'started life' as the Omni-Bearing Selector related to nav beacons long before Satnav was around, so surely it should be available when using just radio aids?
On reflection I think I really have 2 separate questions. The one about how to control when the OBS/SUSP key appears is a specific one for which I can't find an answer in the literature.
The other is more general. Garmin produce shedloads of reference material which they make available free; so far, so good. But it isn't really high-quality teaching (or self-teaching) material. I take your point about trying a simulator, but the one available to me at the club costs a lot. On my home PC I run Garmin's own 'sim' package, which wasn't expensive but just doesn't work very consistently – not well enough to convince myself that the details are a true representation. So what I would love to find is a well-produced guide of 'how to do it' going through, for example, a complete Nav sortie using G1000 from departure to Missed Approach, with and without the autopilot. To be fair to Garmin,there is an example cross-country in the G1000 Pilot's Guide for Cessna Nav III, but it is a bit short on detail. (Para 5.11 Navigating A Flight Plan). If others have worked through this example and found it fine then I guess the problem is me! But if anyone has found something better, I'd love to hear about it.