Panny 65" V10 Inquiry

Hi,
After listening to all the advice and spending hours and late nights reading analysis and reviews, I made the switch from my Darling Sony 46' X-series to Plasma (Hope I won't be disappointed?!!) I went ahead and ordered the Panny 65" V10. It'll take few days before it is delivered.
I have the following Questions:
1- Is it recommended to hang it on the wall? or is it too heavy, too big?
2- As my viewing distance is 13.5 feet = 4.1 meter. I watch a lot of SD programs 60% of my viewing. Did I make the wrong screen size for SD viewing from this distance.( I also watch Blu Ray which I think is no issue)?
Many thanks
GB