With respect to my comment on foot pressure, I noted that depending on whether I pushed against the bulkhead, the boat tended to steer itself to the left or right. Perhaps that has more to do with weight shifting on my rear as a result, but I'm not sure. I get the sense that I don't want my feet just casually laying around in the hull, but that I want to have feet and legs bracing against a footrest/bulkhead/ and top of hull, respectively.

Most boats will turn just by 'edging' (to use the kayak term) or 'heeling' (sailboat).

So, it's quite important IMO to be able to have good edging control in a kayak - not 'wedged tight' into the boat, but snug enough that you can edge the boat easily.

In a good boat, you can save a lot of course correction strokes by just edging the boat to one side or the other.

You should be able to lay one leg against the hull and the other one up against the deck underside if the footpegs/footboard/bulkhead is in the correct position. This gets pretty important for rolling as well.