Got lots of scraps, can I toss a piece into my fireplace every once in a while?

I wouldn't. Unless your fireplace draws a lot of air up and out I wouldn't take a chance subjecting myself/family to the possible toxic fumes it could get off.

i use it for kindling to get the fire started. never had a problem. and i'm ripping out 1200 sf of it.

Maybe in small quantities with a very good air draw. There are chemicals being burnt off that are not good for you that you don't want to get in your air.

It's not just wood you are burning. Burning pre-finished flooring adds good amount of chemicals into the mix. Would anyone want to breathe the fumes burned from OSB?

in an air tight fireplace, a few small pieces just to start a fire isn't going to hurt anyone.

I wouldn't reccomend it. The amount of toxic fumes and potential health hazards aren't worth it. Just throw it out with the trash.

??? Does your house fill with smoke when you light a fire? If so, don't burn scraps or anything else. If, on the other hand, your fireplace is equipped with on of those chimney doo dads I have been hearing so much about, it does not matter what you burn in it.

p.s. Smoke from unfinished wood is toxic. Be sure to have a chimney.