They are establishing him as an emperor. Through fear, and "bark", for NOW.
Well there isn't any bite. But that for the moment is okay. The only issue I have is when Ronan told him he was coming for him. Right before that, Thanos seemed to be getting angry. And after the threat Ronan made to him, Thanos just blinked off the seem, making him seem like, well..I'm not too sure. I didn't like that though.
Dude, Come on. The collector thing was a bit much, yes. But he's providing some pretty good points. He's presenting facts, and DOES have a bias.
Stop making judgements from the peanut gallery lol He's a die hard Thanos fan, who, despite what any of you seem to think, DOES know Thanos probably better than most...short of myself of course

. But he's presenting his opinion on the matter of Thanos, based on what he's read, and are altered by bias. Calling someone delusional, doesn't win an argument, and an argument, or discussion can be carried on easily without pointing fingers or calling names.
Personally, I too am not thrilled how Thanos is, simply just because of what Ronan said to Thanos during their last exchange of words. However, I get that they were trying to show the power of the gem, of someone who is mad.
Thanos has been threatened multiple times by lesser beings in the comics. Hell, Infinity Revelation, the Silver Surfer who has a history of being viciously beat down by Thanos said, "Titan, I warn you..." It is what it is.
They are establishing him as an emperor. Through fear, and "bark", for NOW is how they are establishing the intimidation. It seems that what we've seen, the only other thing they are trying to establish aside from the word of mouth within the MCU, is a personality. Which we started to get. We saw his face at the end of Avengers. In gotg, we got how the universe views him, and a little bit of a personality. It's fine for now, however...if he doesn't show anything by his next appearance, then yes, I too will have an issue.