Mmh, hello ?
1. Penny literally helped Orion win the implant to go to Eternum.
2. The entire section in the warthog server wouldn't happen without her.
3. Her role during the heist.
4. Also pretty sure neither Orion nor Nova would have been at the party if it wasn't for Penny inviting them.
5. Her role during the vampire/werewolves server.
6. Send amazing pictures of her own bosom and of Dalia's butt to Orion (yes, that counts as motivating Orion which is good for the team, change my mind

).
I'm probably forgetting some things, but damn do some people need to learn how to appreciate good character writing. Sheesh.
to play devils advocate, though i can agree with you that her involvement is not unnoticed it is hardly irreplaceable.
1) Penny only helps with one question and your argument for that would be more valid if final result is always 1 question difference but thats not true, you can win by a landslide if you guess everything right (aside the imposible question that you cant guess right and you only have a choice to be wrong by listening to chang or by your own fault), so technically she did nothing there but it was a nice inclusion of her character in the scene and it surely shows her personality... i would hardly say it can count as proof she contributing to the team.
2) warthog server was wholesome and it really made me like penny as character thanks to taking a glimpse of her memories but overall one can argue that whole server is a filler episode because if you remove it nothing is taken away from main plot (looking for gems of doom, unraveling secrets of eternum, finding out the truth about founder etc.)
3) i think anyone can play the role of bimbo being staged killed and worst case scenario they can just think of something else. Her role in heist was more of a "throwing a bone" to someone rather than giving them role only they can fulfill
4) this is absolutely true, orion (nor Nova for whyever that matters) would not go to that party, though again they would just play games in eternum or do something else so again, filler content, nothing regarding main plot is learned in that party other than some weird shenanigans if orion gets high which can also easily be discarded as evidence as it would not hold on court.stuff you see while high are not credible although i understand we can meta game and look deeper into it because we know its a game.
5) her role during vampire can easily be filled by orion and have him skip the dilemma of choosing where to go, after all by going to investigate the stuff Penny did you dont lose anything from Luna's path because if you are on her path you can find her in the barn and get her scene even if you choose to go with penny or in this "what if" scenario if you two split and you go to investigate what penny did without her.
6) this just proves my point i am making that she is just filler content and not that important.
lastly i want to say i really like penny and even though she is not very high on my personal list of favorite girls i do think she is well written, i just love being devils advocate and showing different perspectives

i would not be heartbroken if story was written without her but i also wont deny that Penny brings lot of nice things on the table though admitedly if you go back and read my previous posts that was genuine and not just devil advocate shenanigans, meaning if you read comments where i voice my opinions and not fooling around you would see the pattern where lot of my issues with games involve penny in one way or another