How many expansions will I have to buy ?

[Kinseykinz]

I already explained how that is gonna work. As for the duties, you can't queue for them if the current platform doesn't have Heavensward installed. It really is that simple.

Actually it is NOT that simple. I could do FFXI content without having the latest expansion so long as that content was part of the game/expansion I DID have. So again, it likely depends on the specific Duty/ Duty Roulette. Any roulette tied to Heavesward? Likely you cannot access without a Heavensward account. But any duty roulette only consisting of ARR content, will likely be accessible without a Heavensward acct/not on a heavensward acct provided that you meet the other requirements of the duty.

Also, it is unlikely that every Duty Roulette will be tied to heavensward content. So basically, some but not all roulettes might be effected.