All sounds sensible but do consider
BA will always offer some benefits. Firstly most singles are not equipped to deal with ice, or thunder storm avoidance. Secondly, an IMC rating will not allow you to fly IMC in France. This all adds up to commuting only being realistic if you have time to spare and a schedule that is flexible.
You will probably want to try a few aircraft before you buy and this will in turn determine whether you do your additional ratings in the one you end up in. Do consider that at first you will find a more sophisticated aircraft a handful which may put you off an excellent machine for your future purpose. Maybe therefore build your confidence on whatever is available.
Good luck