Questions on certain points of the first book!

I'm loving the first book (right now reading "Rescue") but I have a couple of questions on a couple of situations that I wonder if may be resolved soon or not. Please answer as spoiler free as possible (aka really light spoilers).

1) I loved the Tuatha'ans, are they going to appear again, have a bigger role or we'll not learn more about them?

2) All Mat's dagger plot is really annoying, how he is behaving etc., Typically "Lord of the Ring-ish", will this finish soon or will this plot continue for a long time without evolving?

Thanks for the answers!!