Question 1)
B. B-NotSupported, C-Required, D-Mandatory, E-RequiresNew, F-NotSupported
Here "B" runs in an unspecified transaction context since its mentioned "not supported". C has an attribute "Required" so it will create a new transaction(TXN-A) since B was in a unspecified Txn context. Since attribute for D is mandatory. It will run in the callers txn i.e; (TXN-A). E requires a new txn so it will create a new txn (TXN-B). Fdoes not supporta txn so it will run in a unspecified txn context..
Question 2)
I am not very sure about this . could some experts throw some light on this..Also to add if a bean is removed then isnt it neccessary for cascade-delete tag be present in the DD for the other bean to be removed as well.???