I think most of your questions are answered in our video and written review: http://www.mobiletechreview.com/phones/LG-Ally.htm . The speaker volume is decent-- not deafening but adequate unless you're in a very loud place (i.e.: sports stadium).
Outdoor screen visibility is average for non-iPhone (the iPhone is better) and non-AMOLED (AMOLED is poor outdoors) capacitive displays: it fades but is viewable.
-------------------- Lisa Gade Editor in Chief, MobileTechReview