Alvador
Your answers are all correct.
Unfortunately you must be :-:G to access the :-: T1 Departures lounge so your best bet is instead of heading to the departures lounge on arrival, exit into the arrivals area and make you way to the :-: Arrivals lounge where you can shower and have something to eat there.
It means you'll have to head back through security but its usually pretty quick in T1 now, I rarely wait more than 10 minutes these days. You then only have access to the DC lounge from gate 5 in T1 with no showers and only snack food to eat. You'll get something hot on the way to EDI if you depart in the morning though.