hey, im new to this forum.
i've got a wrx 2001 (here its the bug-eye model, which i think you started to have at 2002).
i've got a prodrive ecu from ebay, about 2 weeks ago, which was mentiod to be fitted to a 2002 wrx.
i need an help about few questions i've got.
first - does it has any different if i got the ecu from u.k, which, as you might assume, drive on the wrong side of the road (RHD) while my car is a LHD?
serials i have got on the ecu are

with marker someone wrote :
IP0172 KF02 PYJ
it has been told by prodrive that those digits fits the prodrive ecu's, as been flashed over u.k by prodrive, that is why there is no prodrive sticker.

i wonder if this ecu fits the bug-eye model of the wrx, and, when i will re-code it over subaru garage, to fit to my key, will it remove my prodrive map on the ecu?
or it is just better to replace the immobilizer i got with the ecu (and a key as well) so i will have them without re-coding the ecu?
what do i need to do for that? where is the ecu and the immobilizer located at? so i will know what to replace? and will it be enough.

got several more questions

i do not have the prodrive muffler (backbox/exhaust) as i have told its only the backbox which has the different, the whole pipe should be the same diameter just the back box. will it make any different if i will stay with the WRX one?
will i need to replace the fuel pump as well? as i've got the original WRX one (i think).
and last question (for now), when i switch the ecu, as much as i know, the boost will raise from 0,9 to 1,1. will it be automaticaly? as it feels like the car has no power now, doesnt feel the turbo before 4500rpm, is it oke? or do i need to adjust something my self, after the ecu will be installed?

is there anything else needed to be replaced? i do have the prodrive hose for the intercooler, btw, does it makes any change when i replace it? or its just added to show that prodrive made the kit?
thanks a lot for the time you've spent reading my questions and answering as much as possible.