Hold on chaps, don't let the crewroom rumours guide you.
1. You can sue the MoD while you're still in
2. Conditional Fee (CFA) or a reputable No win no fee charges costs to the other side, no slice of your payout.
1 & 2 - I should know!
Most solicitors operate a 'first half hour free' policy. This can equate to an initial e mail, followed by a second more detailed e mail exchange.
'Litmus test' comment is spot on - good case or they won't take you on.