Since I have more ideas than the voting system is going to let me suggest, I’ll suggest them quietly here.
It would be great if the texture tinting system could do something other than darken. Something like the symbol tinting functionality in Flash would be great, but something simpler would be fine. So… replace the current single color choice with color and texture strength. Default that to 100%, and at 100% it works as it does now: full strength colour change, white being no change to the texture. At the other end of the scale, the texture fades out, so that you can use a texture as a lighter tint.
What else? Scrubby sliders. They exist in the latest Photoshop and Motion, but not many people use them. Instead of using the little buttons or an existing slider, click on the label of a control (like opacity) and drag from side to side. Finer control without clutter. SL could really benefit from quick, accurate adjustment like this.