Hi, I also echo this sentiment. Especially for all core code. There is a thread noting warnings in core code elsewhere in the forum. I believe all warnings may be eliminated upon careful examination. In C/C++ explicit casting can usually accomplish this, and other techniques are also available, each situation/solution having its own merits. In my experience warnings are like bug-eggs waiting to hatch, and when they do, the little blood-suckers come and byte me!
I also understand this is probably very confusing for beginners, so default verify/upload (build) should continue to suppress warnings.
I would suggest only turning on all warnings (compiler option -Wall) when the shift key is used with the verify/upload buttons/menu-items. The warnings are then identifiable with the compiler call/module to which they relate. (There should be two additional menu items Ctrl+Shift+U and Ctrl+Shift+R to complement the button bar functionality).
I would like to make this an official change request. Is this forum the way to proceed? If not, may someone point us in the right direction?
Many thanks for all the work already done on Arduino, I love it, I want more.