the frame is powdercoat..
yes it would add some weight, but not much !
The bikes quite a bit lighter, than it was as a KXF450 ,
and also now has a bit more hp..
so a few ounces arnt going to be noticed much ;)
as far as street legal?
not at the moment..as it only hjas heradlight /taillight.
here in Indiana it could be easily plated and *street legal*
with the addition of a dakar type kit ?
basically brakeligts signal, horn made for a dirt bike.
other states regulations are different, some are fairly easy to plate an off road bike, others are extreemly difficult.
it varies greatly state by state.