as long as your brackets and basket chains can take the weight yes. You may have to feed the plants sooner as the soil wont have much in the way of 'food' compared to composts.

I'd say yes, add some growmore or such like to it.

The only thing that comes to mind is the possible weight when wet & full of plants, plus any residual wed seeds lurking

I think you will find that the soil will become very compacted so I would resign the soil to the garden or perhaps a light covering on the lawns. If you feel that you must use it then a mix with slow release granules.

You could mix it 50/50 with bought potting compost which is much lighter.

Hi Guys
What I have done is mixed about 60/40 topsoil and compost with a bag of perlite as well so that should be fine I hope

Did you add some slow release fertilizer granules as well?
Sounds as though you have lots of baskets - pics please when they all flower!