Hei, thanks for your feedback. Changes done, use the same links in the first post.
Faster input was already provided by the mouse wheel - try to rotate it over the properties, i.e. Spray Cone step is then 5 deg. It is working for every property with a reasonable step. Sorry for not giving a clue about that anywhere on the page.
Actually I'm missing the Tooltip option for mouse over a Sprite (and I'm a bit ashamed because too lazy to implement it from scratch). Actually this option exists for mouse over a Button.
ON-OFF feature improved, now it is working properly. I don't need to resize the buttons, because you can now click everywhere on a particle spray to turn it on or off, including the small button on the bottom of course.