Have you noticed that a number of people, particularly younger ones, when talking to you often say, "right?" at the end of a sentence. For example, "He should have known that, right?" It's hard to write about it because you really have to hear the tone, right? It's not the same "right?" that people used to say. The tone makes it different.
many people now begin sentences with a conjunction
But, people have been doing that for centuries. Again, not really a matter of grammar but one of convention and punctuation. Often the pause between the end of one clause and the start of the conjunction + clause is longer than a comma or even a period. You see this a lot in older literature.
We've always used the word right in a confirmatory way, but more recently it has been used more frequently, I think, and with a different tone. It's hard to explain in writing, though it would be easy for me to tell you.