Hi Ricardo.

The Captain Sim 757 v4.6 should install into FSX-SE perfectly fine, and it should work okay.
The only things that I can think of at the moment that might not work properly are:
(1) The ACE might not work.
(2) The FMC might not be able to load FS Flight Plans due to the fact that it will look for them in Documents\Flight Simulator X Files, instead of Documents\Flight Simulator X - Steam Edition Files.

I hope this helps.