Chris,
For example, I know that at that time music was becoming more entertainment, more secular. Would this indicate the wheel size and crank size would be getting bigger so that players could play longer, or the wheel size and crank size getting smaller so that players could play more brightly and lively?
Rather the opposite is true. If you want to play longer, a smaller wheel with a short crank is an advantage because it minimizes the movement of the hand and wrist. The Hungarian instruments have quite small wheels and cranks, and if players really want to do the historically accurate thing of playing three-hour csárdás sets, they actually get special shorter cranks to do just that.
In any event, until multiple-ply wheels were in use, your practical limit for wheel size would be not much more than 14 cm, so in the early periods you are talking about you wouldn't find large wheels at all.
Best, Arle
