Can I use scratched hotbed?
like this:
I’d say yes. Do you print direct or cover it with tape/buildtak/etc?
If covered, no problem. If direct, the scratches shouldn’t affect adhesion or structural integrity of the prints, but will be part of a “signature” stamped on the bottom of every print you make.
You could always use a raft if printing directly to avoid the signature making it into the face of the part.
@Alex_Wiebe Thanks. I will print with tape, or something.
If that is on an aluminum base plate then you can lightly buff it with steel wool to remove any sharp edge and burrs and cover with Blue tape and you woun’t even know it is there.
I’d check the nozzle that made the damage if you havn’t already. It might not print like you expect it to anymore.
I think you are fine. A light sanding w an orbital sander over the entire surface won’t hurt your prints and will hide the flaw. It’s fine 
Yes. It can be like Dali’s signature. Just keep care if you print a clock it can finish a little wooble (?)