Hello, that is hard to diagnose with photos, but it looks like there may be some scorch from our late June heat wave, re: the yellow leaves, although there is a common foliage disease (cedar leaf blight) that can cause similar symptoms.  That should be something the tree outgrows, so a normal thing.  The foliage doesn't look too bad.

Relative to the dead twiglets.  That looks like something different.  I'm not sure what it is, but could be several things, including a more severe scorch effect (we've seem similar things in the coast range where cedar got hit hard) or perhaps a canker disease (which should not kill the tree), or even some animal or insect feeding on the bark?  Check at the base of the dead portion of twig for feeding activity.

But in general, cedar seems to do ok eventually and may lose twigs and foliage a bit as it grows.  So I would not worry too much.