I was in a similar position, except that my first saw was an 064 with options of a 2ft bar, or a 3ft Alaskan. This pre-dates CS30/31, but nonetheless some training of some sort might have been/be useful! The point being, it's not just about cutting up the odd bit of firewood, sometimes if you have access to woodland you are inevitably felling, and that doesn't conveniently stop at 'small trees'.
In fact, the first thing I felled was 4ft6in oak, standing dead in a field. Perfectly sound timber and textbook cuts (really) and it still fell at right-angles to where I wanted it after snapping the perfect hinge clean off!
I suppose things were more relaxed then, and I was lucky with the people I spoke to who were happy to show me how to go about what I was trying to do. I was having timber milled with a portable band mill at the time, and the owner showed me how to fell etc. Another person (tree surgeon) showed me how to limb up on a different tree, and the knowledge built up.
The advantage amateurs have is that they're not being paid to do a job quickly. I'm always mindful that the tools I'm working with have a lot of power, and the potential to kill me. I can take the time to assess how to deal with a particular tree, and if I don't like the look of it I can leave it alone.
Even now, probably 15yrs on, I would still be interested in some training - not because I need it to be allowed to do what I do, but because it would be good to see what bad habits I have inadvertantly picked up, and fill in any gaps in the information I've gleaned. It's possible that I am sufficiently uncommon for nobody to be interested in running courses along those lines, but maybe with the rise in firewood prices, the availability of saws of any size to anybody on ebay for a few hundred and the relatively easy access to Alaskan mills (and the pleasure of milling your own timber) which inevitably means using bigger saws and cross-cutting to length before milling, there may be enough interest to warrant something?
Alec