Too many HDMI Sources

I have just changed my projector from an older DLP to a nice new PT AX100E Panasoinc.This as usual shows up poor performance of other units.

So the ideal situation is I upgrade my sky box, I change my DVD to a 1080i upscaling HD player, my Xbox becomes a Xbox 360 and I throw in a multimedia PC and a digibox with hard drive all of which have HDMI outputs. I have an older sony amp and speakers that dealt with my component inputs for the older projector, I was thinking of changing to a newer 1200 amp. This is a long project and I would like to start and set good foundations for the whole system

Here are the questions

1/ How can I manage to route all of the five HDMI signals to the projector- using a switching box?

2/ How do I get the best sound quality  from the units to the amp tos link or cables? 

3/  What is the difference between HDMI standards 1.2 and 1.3

4/ What is the maximum run of HDMI cable it is safe to use before you start to get signal loss and pixelation

I am sure if you answer these I will have more to come

Thanks in advance for your help