The description of Adrenal Moves: Speed says that it 'allows character to move at twice normal speed (as if hasted)' and thus increase his activity for one round as described in Arms Law.'
The Companion II version also gives some help for interpeting this in the initiative system introduced in Companion I: 'If using the initiative system [in RoCo I]..., his actions for the round... are all at half cost.'
Yes, and Arms Law is pretty clear in a number of regards:
- it reiterates that a hasted character (not merely from the Haste spell - *any* form of haste) may not fire more than twice a round
- it also states that "(a person) must abide by the sequence restrictions. That is, whatever activity the person takes will have to occur in the proper phase (thus, a hasted person could notmove, fight and then move again, denying his adversary the chance to swing back). A hasted person could fire a bow, move, and then melee, OR attack twice in a melee phase (once at the beginning and once at the end."
To me, it all makes a pretty clear picture that you cannot attack more than twice in a round regardless of how much haste factor you accumulate.
(also, that section of Arms Law - that's section 3.6 - is pretty explicit about the fact that "casting more than one spell/round is still prohibited". The one spell per round rule also transcends any kind of haste).
Overall, I think the best you can hope when you cumulate several haste factors is to be able to attack twice (any combination of melee and missile), move, and cast a spell (not in that order) - this is pretty much the only combination that is allowed under the sequence rule (given the sequence rule, you could not prepare AND cast in the same round either, since both actions are in the same phase). Given that melee attacks are at most 100% activity and spell casting is at most 75%, the only benefit of going above 200% activity would be that you would be able to perform a longer move - which can be a significant benefit, especially if that move is a complex manoeuver.
But my take on all that is RM rules were never meant to allow a character to transform into a whirlwind of steel.