I recommend you searching for your answers considering 2/3 of those questions were found in the first two pages of the M&M forum.
1.
http://www.flyertalk.com/forum/miles...-config-f.html
3.
http://www.flyertalk.com/forum/miles...lounge-38.html
LH's F seats are not suites and the better F seats are on the A380 and B747. You won't be finding availability whenever or wherever you want to go somewhere on an award ticket.

You can always book the JFK-MUC route and look at the availability of the JFK-FRA route day by day to see if a F seat opens.