On motorcycles, can a lot of gearboxes be transfered from one model to another, e.g. hayabusa to a bandit. I am wondering how it would effect power delivery?

No.

In a word, no, most bike engines within the same manufacturer are derivatives of one another, e.g. Yamaha Fazer and R1, but in reality few parts are interchangable.

Gearbox is cast into the engine block... so no possible way of swaping boxes atall..

Some internals might be swappable... but it would be a nightmare trying to work out which bits would and wouldnt fit...

All 919 Fireblade gearboxes are transferable in their entirety between engines. However, even on one bike from one manufacturer they are all different from year to year!