You've got well thought out and totally valid arguments, but to keep it simple and stop myself from writing a wall of text, I'll keep it short and sweet:

I disagree. She does have video game knowledge, and just because you may not necessarily have knowledge on game design and such, doesn't mean you have no right to comment/joke/whatever. She stops conversations/topics just as much as any of the others do.

In regards to the improv/comedy skill - it doesn't matter. You don't need improv training to be funny. Comedy comes when comedy happens. A huge chunk of the time we aren't laughing at Arin and Dan's improv, we're laughing at them raging or at glitches in a game. That's not something you can teach, it's just natural reaction. To all of them its' just about having fun, and to the average Grump fan they'll have just as much fun watching the episode as long as they're having fun recording the episode. It's their form of comedy to bring to us - not ours to dictate to them how they're doing it correctly or incorrectly.

In regards to them "not being themselves", it's totally possible that that is their normal selves - who knows, maybe the guys being "gross" is the actual charade, not the other way around. To Suzy offending fans - I think she had every right. If tons of people ganged up on you and made you feel like shit, wouldn't you get upset too? She's a person just like anyone else. Being a YouTube personality doesn't give people the right to shit on her and it doesn't take away her right to fire shots back (blam blam.)

Well shit that turned into a lot of text anyway, oh well. In the end, everyone has their own opinions on her and no one's text posts are gonna really change them. My point that I care most about though is that it's their show. They have fun so we can have fun. They don't owe us anything, it's us who owe them for giving us so many laughs and good times - each and every one of them.