few questions about normals

[slavke]

alright, I am into a game development and have been busy making low poly models. Now I got to learn few things about adjusting normals. My first problem is when I detach chunk of a model lets say a bumper of a car the sharp edge shows up on the outline of the detached object so yes I know I need to adjust the normal to line up with the other original object so it stays smooth. The thing is it takes such a long time to adjust one by one so I thought you guys might know some fast alignemt like sort of a snap or something. Also since I work in editable mesh or poly and use lofting I want normals to remain on it but when I collapse it , the thing goes back to normal again and changes do not remain.
Thx for the help...