Hmm, since it's not that long ago, that I played that quest, I remember it and it's aftermath well.
About Cullen:
First it's Cullen, he was never gifted with great emotional intelligence and I think it would have been odd, if he just now started to get sensible - that would have been out of character. He is always a bit awkward. Plus in this special case, he was sure, that he wouldn't survive either, he said so.
Roderick:
I liked, that they made him a hero in his own small way at the end. I always found it strange, that your character can only be rude to Roderick. I had wished to tell him something nice in the end - unlike Cullen, my character is not socially awkward 
Cass & Co leaving you:
Wasn't that the plan all along? They help you with the trebuchet and then get the hell out, because it was more likely that Cory would simply kill them, while he at least get into dialogue with your character before he makes an attempt to kill you.
Only 6 people dancing:
it was the 6 people, you had to save and it was a scene to help you remember those.
Josephine asking for a flag:
Of course she would. If it was some nobleman attacking, she might have been able to manage to get at least a chance to negotiate, because sheprobably know most of them
Only Cass running to your side:
it was chaotic, most people were still struggling to stay on their feat. I had Solas, Varrick and Dorian with me and they all still were getting on their feet again - Cassandra just beat them to help my character up. I don't see anything wrong with that, it's not, like they ran away or something.
I think it's legimate to critizise, but in this case, I just can't see it, sorry. The only thing is, that I wished, I could have said something mean to Cory, I find all the answers too calm and nice for that encounter.
And I know, that most points were already answered in this thread, I just thought, I bring them together. And yes, I admit of being a fan of the Dragon Age games, otherwise I would not bother with this Origins tool (I hate it, personally, with passion
), but that does not mean, I can't understand critic, but some things, the threadstarter complains about, are wrong. You can't argue about wanting to say goodby to the love interest (in this case, I think it was Cullen?), because that's just personal opinion. I would have liked to say goodby to Varric and Cassandra, because up to this point, my inqui probably had the most connection with this two, but it makes sense not to do so, because there is simply no time for that.
BTW: I'm no native english speaker too, but I never got any mean comment, although my grammar and wording is probably off sometimes 