Ok two questions, If I have to chars with Dornish Chariot participating do the effects cancel each other out in a good way or a bad way, and secondly can that char still be a target of stealth, I would tend to think so, however I figured I'd ask as I am new to the game

Each card is resolved separately.

So Chariot character #1 removes those keywords from all other characters except himself when he is participating. Chariot character #2 removes does the same for all other character except himself. So yes, Chariot #1 hits character #2 and Chariot #2 hits character #1. I'll leave it to you to decide if that is good or bad.

Opponents character will not lose their stealth until the character is participating. When you are the defender, your opponent assigns stealth before you can declare the Chariot character as a defender (making it participate, making the attacker lose Stealth). So yes, the Chariot character can still be bypassed by Stealth when you are defending.