Friendly reminder that most home kitchen knives don't need frequent sharpening. Honing the blade is usually all that's necessary unless there's damage to the edge (which shouldn't happen much if you keep your blade honed).
I haven't sharpened my daily driver chef's knife in 7 years, and it can still slice through a tomato with no effort.
Never make the mistake of letting people know you can sharpen knives. Apparently it's a lost art, you'll end up with a tray of them in your lap when you're over for movies, in my experience.
Yes, it would be. The main reason things aren't dishwasher safe is the detergent or heat can damage the material. Food grade stainless steel would be fine with both.
And, how can you tell it was sharpened from the picture? Usually, when I've seen sharpened knives, the cutting edge has scratch marks perpendicular to the blade and is wider than normal from being grinded into a longer slant.