Nothing like it
Saif;
First off there are no guarantees here. You get left seat by selection not by seniority. So you could get it right away if you are a star. Have a hick up or personality clash and all bets are off.
Yes 3yrs DEFO then transfer to pax WHEN a FO position is available AND they can afford to let you go to the freighter. That depends on the staffing on the freighter and whether there are a lot of new hires on the integrated FO positions (they will fly all -400 eqip in N. America base)
As for the move to HK you go on the 400 and that is it. They will ask you to fill out a form saying you will accept anything but will not move you on to another type. So it is all a game really. If you decide to wait for a N American basing you may have to wait a long time as they are filling and will remain filled once full for a long time.
If you are hired into a Base on the new unified FO direct entry you will keep your base for as long as it takes to hold command or you move to HK Europe etc. That is looking like it will stretch to 15 or so years if you choose not to go back to HK.
So if you are being hired find out into what position as it will make a lot of difference down the road.
Just my five green cents