Hi Carl! (it's Chris... not Dave
)
I don't have the luxury of a shop (yet) so I'm set up in living quarters. Because of this, I fully clean everything just about daily. Haven't had any issues with the window or sill and I can't really set up a guard or backsplash because I fill that window with 4 powerful fans when I'm running the grinder which do a good job of drawing out the dust and all.
I use the platen quite a bit when grinding bevels, squaring spines, some scale work, and generally grinding small surfaces that need to be flat. Also helpful to me for getting dovetail bolsters and things of that nature to fit correctly. I should just commit a ratchet with a short extension to that instead of the gear wrench.
Good solid advice on the renegade sparks, I'm very aware and definitely have a spray bottle hanging nearby.