I have some pre bonsai Pyracantha, and am planning to start working on them. My first issue is what do I do with the thorns: leave them or remove them? Do they grow again?

Further, how do I distinguish between angustifolia and coccinea?
Thanks for any help on both questions

If you remove the thorns it will not flower. I discovered this the hard way wondering why mine did not flower. I would not remove the leaves.