A PA CCL doesn't include knives, it only covers firearms. PA blade laws are pretty vague. Apparently, PA has dropped blade length restrictions but there are also local ordinances to consider that may have limits. My locality has a 3 1/2" blade limit by city ordinance. Problem is, the PA code (908, I believe) contains the language "common lawful purpose" as to what is permitted to be carried legally. Basically, if you run down the street waving a butcher knife or a Samurai sword, the cops are probably gonna' give you problems. The only knives really specified as illegal, are ones with the "brass-knuckle" style handles and anything "automatic"...like switchblades. As far as I know, butterflies are still legal.
Throwers would likely not fall under the "common lawful purpose" definitions of most LEOs. I've carried throwers for most of my life but I carry them with purpose and keep them concealed, they're not jewelry. I carry them as a backup because I'm familiar and comfortable with handling them, not because I'm naive enough to think they'd ever be useful as a "thrower" in a SD scenario. At the most widely accepted SD range (7yds or less), a good throw is unlikely under SD circumstances and at best, you're throwing away your weapon and possibly just adding it to the BG's arsenal. I also doubt even a close range throw would be seen as defensive by most LEOs and courts. Throwing is basically reserved for sport or assasination, any self defense with a blade had better be well within arms' reach. IMHO, throwers are technically illegal, according to the PA Code's definition of "common lawful purpose" but if you carry them responsibly and concealed, you shouldn't encounter any problems. Still, be aware of your local ordinances and pray you never need to draw your blade.