We pick the candidate with the majority of support at the convention. We always have and nothing has changed. If Trump doesn’t have the majority going into the convention, the delegates that were pledged to other candidates might give the majority vote to another candidate. There is nothing unfair about this system. It allows you to vote for your principles in the primary.
Yes, very orderly. Until during the middle of the voting season, they come up with a strategy to intentionally come up with a different "principle candidate" than those running and being voted for.
Now, let things proceed according to your tried and true method WITHOUT articulating a strategy to thwart that very process BY INTENTION. Then you would be talking.
If you can't understand this, if you are pretending that every primary season sees this kind of activity and according your post things are just going right along as they "always have and nothing has changed", then you aren't a very honest person or you are a very naive person. One or the other.