A Few Simple Toy Box Questions

When in the Toy Box HUB, can you drop in toys to mess around with? (mainly talking about just dropping in vehicles and such)
Can I just drop in the Ghost and fly around? Or do I have to build/start a whole new toy box of my own to access the toys that I buy?
Is there was to use unlocked/purchased vehicles in the play sets? (For example, instead of flying around in the Jedi Starfighter can I do the space missions using the Ghost?)

Thanks for your help!

Play sets are locked down and you can't use any toys in them. You have to use whatever is set up in the play set.