1. Is the LCD bright enough / large enough print for live applications? It seems that depending on the view it would be difficult to see on stage.

yes, there is a "Big User View"

2. Can you via the footswitches change setlists? I play in a band where we call alternate tune selections often depending on the crowd reaction, so not having to bend down and push buttons would be ideal.

no, you can change patches and banks

3. There is much talk on this forum that get consistent volumes across patches is difficult. I would assume all I need to do is run the output of the HD500 into a mixer and verify the PFL level is consistent across patches. So the trick is to set the amp volume output consistently across patches to make this happen. Is this thinking correct?

yes

4, I currently run the output of my older pedal board instrument level into a quality DI box with very good results. Are the XLR outputs nice sounding? I'll be going direct to the board.

yes

5. I am confused on the input impedence setting. Is this the impedence of the guitar output to the HD500 or is this the first thing in the signal chain? Why not always use "auto"?

...first block in the chain... "auto" is a good choice

6. This is strictly for live applications...is this a great gigging board? There seems to be a great deal of people recording with these but what about live??? comments appreciated!

...very good for live gigging!

7. But is true that also makes coffee?

maybe, but you have to check the manual to find out

Thanks, that's it for now...

to serve you, always at your disposal