4)
My experience a few weeks ago:
* Wait for boarding to start
* Proceed to first booth - get ticket
* Proceed to second booth - present passport
* Proceed towards ferry
* Hang around in arbitrary holding area with other cyclists and motorcyclists, as directed
* Await permission to board ferry, board ferry
There's nothing inherently time-consuming in the check-in process, so I guess you just want to make sure you get there before check-in closes. Things will be a lot easier if you're not trying to manoeuvre a cycle through a deck that's full of vehicles and people making their way to the stairwells.
3)
If you overlay your route onto an Open Cycle Map background, you can check for cycle shops (yellow markers)
2)
If you overlay your route onto something that does a street view - Google or whatever - you can check to see what infrastructure is present at different points. I would imagine that, even if possible, 16.5 mph would be inappropriate for the bounded space of urban cycle paths shared with other users. If your route takes you along open roads (so probably more rural areas), or you've a long, straight run on a less busy path alongside a motorway or estuary you'll be more likely to be able to maintain your top speed.
http://www.strava.com/activities/1848478817 <<< I cruised along with this club ride (see photos) in the dunes for a bit and it seems they managed an average speed of about what you're aiming for. So maybe, with some careful route planning and a favourable wind direction...
