I wonder if you are not taking an F27 down ??
Anyway , just a few thoughts . I had to do that reverse some years back (to the US , I mean ) . As a US citizen , you don't require a visa for the shengen zone BUT that doesn't apply to people arriving by non-commercial airliners/ship .In fact the shengen visa doesn't even exist for this case .Aircrew normally get another type of visas (like the class D in the US) if required .Normally your flying license gives you a couple of days free-transit BUT as the US requires aircrew to have a D-visa , the EU will have a reciprocal rule .As a non-commercial operator you can't get those , so you need to apply for a specific business or transit visa as required .Basically the only real answer I can give you is to give a call to the nearest consulate of ALL the European countries you are going to transit .Be aware that not having docs that you have never heard of might lead to a hefty fine (a friend of mine got fined 2000 US in
PR some years back on a ferry not realising he wasn't covered by the visa waiver program in that case ). Regarding Africa , most Normal countries there will let you in with a license (and uniform) for up to 3 days or allow you to purchase a visa on arrival if necessary .Some states have different rules depending on current relations with the US (Sudan for ex.) .Another call to your state department might be useful to clarify that .Best of luck anyway and have fun .