You don't need MOT's and FSH to enter concourse as far as I know mate.

For your first time your better off entering the Novice class and seeing how you find it

I'm also sure that for Novice you don't need to have the underside and arches done! Just clean EVERYWHERE and you'll do fine!

Mod's are ok to so long as you enter the right class, concourse logbooks can be had on the RSOC iirc