Just a very quick dvar Torah: Chizkiah could have been the moshiach (see here:http://dreamingofmoshiach.blogspot.com/2008/04/rav-chizkia-shlita.html) but he chose to learn Torah rather than sing praises to HaShem.
Of course as Jews we need to do both Torah and Tefillah, but sometimes it's the time for Tefillah and not the time for Torah. So, next time I think, "I'm in the middle of learning, I don't need to sing Shabbath Zemirot," I'll think twice.