For 1): Chapters 4-6 (this is a single bound text) of Bourbaki's *Lie Groups and Lie Algebras* is often said to be the most comprehensive introductory treatment on root systems.  Much modern work in linear algebraic groups and related finite group theory makes reference to it.  

(In fact I have heard it said that this is the high point of the entire *Elements of Mathematics* series, though this is obviously a matter of taste.  For my part, I believe I currently like *Commutative Algebra* the best.)

For 2): apparently yes.  See e.g.

http://www.sciencedirect.com.proxy-remote.galib.uga.edu/science?_ob=ArticleURL&_udi=B6VJN-4KH8557-3&_user=655127&_coverDate=03%2F27%2F2006&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000033918&_version=1&_urlVersion=0&_userid=655127&md5=a5c73380335db9bf48036ebc5daef14d&searchtype=a