Hey there ASR
I used to own one of these babys. Good machine for the price.
Might I suggest you do a google search under sunbeam ristretto site:coffeesnobs.com.au you will get a mountain of hits. Maybe some will be advantageous to your quest in getting the most out of the machine (you will probably also find I have asked similar questions when I was at the same stage in my coffee life)
As for the steaming - your technique sounds solid enough. Again search for steaming techniques here. Good steam technique is pretty much universal to all machines, it will just be the amount of time it takes and a few little machine apecific nuances that will change. The ristretto is increadibly slow to steam, you are right, but sometimes that is a good thing as it gives you time to watch your technique and make sure you are not under/over stretching/frothing etc. Keep at it and read up on the search hits there is a lot of good discussion there which I know I benefited greatly from.