On the tandem, I do go ahead and run them at the maximum (minus 2 psi of roundoff).

On the shifting, I can look down and see the front rings okay, it's just the rear that can't be seen. Although that's usually not a problem for me.

If you and the stoker both unclip the same foot when you stop, no problem, you can work out starting and stopping pretty easily, just like a regular bike but with two feet down.
If one is right-footed and one is left-footed, it gets more complicated. In my case, the way we handle that is the stoker clips both feet in before we start and stays clipped in until we're stopped. That means the captain gets to handle bike+stoker weight at intermediate stops, etc. In that case, when you unclip, put your foot out farther than you normally would.
You need to anticipate downshifts more than on a single bike. If you're coming up to a stop, don't get caught in Monster Gear trying to take off on an uphill. Downshift before you need to coming up on hills, so you're not dropping a chain when you try to downshift at full power while teetering along at 5 mph.