After 2 days of cure in my latest application debris that blows onto it does not stick. A blower blows it right off. I doubt you need to worry about that.
https://www.homedepot.com/p/Sikaflex-10-1-oz-Crack-Flex-Concrete-Sealant-7116110/300934565
No caulk will allow staining after application. I would suggest filling the cracks with cement (No gravel) and then stain. I would also warn you that unless the stain is fairly dark, the areas that were cracked will likely be at least slightly different in color than the rest of the existing concrete.
NO! For asphalt only, such as roads and driveways.
Yes it is water clean up as long as you do that before it dries on your clothes, hands, trowels, etc. I found after it dries, go-jo hand cleaner works very well on your hands and tools & nafta bar soap works well scrubbed on your clothes or gloves before machine washing them works well on those items. Neither of these works all that well on cement adjoiniing your driveway surfaces even before it drys (I learned the hard way to masking tape those edges before applying this crack filler or liquid crack filler!)
It somewhat depends on how deep the crack you are filling is, but typically you are ready to go in 2-3 hours.
Dunno'. I'd be concerned that the asphalt nature of the product would bleed through any paint. If you're gonna' paint i you're probably better off with a caulking, like Lexel or a paintable polyurethane like Sikaflex. This also does shrink, making painting more problematic.
I used a plastic trowel and work it just as it came out of the tube, keep the trowel angle against the tip of the tube when applying it the pressure will force it into the crack.
it will stay flexible.
to some extendt but I found that some weeds still manage to poke thru in a few spots.