Wasp, Badger and Crocodile in March 1945

[TColvin]

I know about the Crocodile. There were 183 units operated by 141 RAC, 1 F&F Yeomanry, and 7 RTR in 31 Armoured Brigade in 79 Armoured Division. BTW, they were brigaded with the 278 units of Kangaroos operated by 49 APC Regiment and 1 CACR. Crocodiles, like Kangaroos, were available to 1 Canadian Army in 21 Army Group by arrangement with Monty who controlled them all directly through Hobart.

What I don't know, and ask anyone reading this for help even if they only know some of the answers, is the situation with Wasps (Universal carrier with flamethrowing equipment) and Badgers (Ram tank with flamethrowing equipment).
Their use is described in Stacey, so that is known.
But specifically, please, can anyone help with these questions:
1. why were they needed? In other words what did they do that the Crocodile could not do? The reverse is obvious. The Germans feared and hated flame and threw everything they had at their tormentors. The Wasp was only a carrier, for gods' sake. Anyone getting into one should have received an automatic VC
2. who designed them?
3. who built them?
4. who operated them?
5. who controlled their use?
6. what was the TOE?
7. how many of each was there in March 1945?
8. what were their losses?
9. was the flame equipment and the fuel used the same as on the Crocodile, or different? If different, who designed and procured it?
10. how many of each were delivered to Russia under lend-lease? There is a Wasp on exhibition at Kubinka.