hated the boot feature! every player had black boots didnt they?
Yep, and you got boots in the ML which you could assign to players to boost stats. I hated it, too.

Is there any way of getting Beckham into the offline game modes? I know you can buy in ML but like actually where you can assign him to a team etc?
I've always heard people say you can with the legends but I've never seen it done.
Yes, you can do this via an external editor.