Planning Permission to Extend Driveway / replace garage?

[salenowon]

We currently have a single garage in our back garden accessed via a side road:



A few years ago we created a new gravel driveway in front of the house. We needed full PP due to being on a classified road, next to a junction and having a number of TPO trees in the garden.

What I'd like to do is replace the single garage with a triple oak car port with storage room above facing the main road (i.e. facing the same way as the house) and extend the gravel driveway over the front garden.

My questions are:

Do I need planning permission to convert the rest of the front garden into a much larger gravel driveway? It's currently unused land where nothing really grows due to the shade from the (TPO'd) trees. We'd access it using the existing dropped kerb at the front.

Do I need planning permission to replace the existing garage with a new structure?

Can any of this be done under permitted development?

The arborist report created for the original driveway PP showed the root system covers most of the front garden and the Council 'tree man' said the driveway needed to be as far away from the trees as possible, hence why it's shoved tight up against the boundary. I'm aware specialist gravel grids exist to protect the roots but is that something we can just do or would we need to involve the Council and 'tree man' again?

Assuming we'll need PP to replace the existing garage with a new structure does it make sense to put in a full planning application covering the garage & driveway, or is there any benefit to doing things in a certain order to minimise potential issues?

Thanks!