It's standard to erhuaize 会 when it refers to time (leaving off the erhaization sounds strange in those situations, and you should erhuaize when reading even if there is no 儿 in the text).

The third tone thing is a colloquial change that everyone up north does - I'm not sure if it holds in other parts of China, but you should definitely do it. I think we may have covered this in one of the shows.