i used to have a hks evc IV and stock turbo and fuel pump. at 123 pounds of boost i had no issues. also i was running stock injectors and fuel pump. now im without a bc and a now have a walbro 255. still within limit without burning up my engine(so far). the MK III ecu is set to run on the rich side, so that should save you a lil bit.
with the lex afm, your pumping in 25% more fuel, and the 550"s pump 25% more fuel. so it all matches up in the long run. that combo also moves fco a lil bit. how far, im not too sure. varies by engine. you should be able to hit more than 14 pounds of boost. how much more, im not sure. you SHOULD be safe.
as far as a fuel controler, i dont know yet. im still in the process of getting one. i would think that you would not need to have it tuned yet.
do you have a wide band? check its readings. adjust a lil from there.