Hi Richard! Welcome to the community!
If nothing else, it looks like Pentax are attracting a bunch of Aussies to the joys of Pentax. The K200D is a great camera as you've already found IMHO.
Don't worry about the Auto stuff too much - most of the scene modes are there to help those with less knowledge of exposure while they learn. Since you came from a manual exposure background you're probably half way there anyway. If not, play with them a bit and see what they do. Fortunately
digital film is cheap
Personally I've found the most useful are P (where I can play with the aperture quickly on on the e-dial). This is almost like the Av mode (set the aperture for the depth of field you need) and let the camera set the shutter speed. Its not a lot different to a manual - you just have to get used to the camera doing things for you!
And you can always get back with that green button.
Don't forget to set up the exposure preview on the on/off dial for depth of field preview - the APS-C format makes the apertures your used to drop by about a stop - but not as bad as the tiny P&S sensors where you really need f1.0 to get proper bokeh.
Enjoy!
Cheers