$450M is the high end that would include a ride. The version that doesn't have a ride costs about half of that price tag.
Yeah, TSL's budget was actually inflated quite a bit because of how it affected infrastructure. People here this big number for TSL and think "What is Disney doing with their money"... well the fireworks launch site had to be relocated due to TSL. Costuming had to be relocated. A lot of demolition took place. Expanded parking lot. etc.
Disney likes to sneak the costs of smaller projects like those into the overall budget of a project, which is part of why their budgets end up being so high. The other reason is because they have money management issues.
It actually really would be. Disney has nothing in their catalog that would work (well, technically the Three Cabs are from Brazil, but a Three Cabs ride isn't happening, even if Coco forces it out of Mexico).
BlueSky is mostly a mess, but Rio and Ice Age are fairly good properties for theme park integration. The question is will Disney use the characters, or will they just sell the animation studio off? Supposedly, according to Jim Hill, think-tank/blue sky discussions have been happening about Ice Age. I have no doubt that he is right and they are talking about it and possible integration now that the shareholders voted yes, but I don't think we'll see it for quite some time even if they do move forward.