Hi. I have a Giant Acapulco mountain bike from about 1995. I bent the large front chain ring, so the front derailleur was not performing well. So, I decided to change out the crankset. It also seemed like a great way to learn more about my bike and how to repair it. Now that I have done so, I am wondering whether I made a mistake along the way.

The chain line is supposed to be 50 mm; I'm at 51.5 mm. The gap between the crank arms and chain stays are unequal--20 mm on the left and 17.5 mm on the right. There's also 5 mm of spindle showing between the interior-most plane of the left crank arm and the frame. Finally, the front derailleur will not reach the outermost chain ring.

Here are the before an after specs on my project:

Before:
Crankset - Sakae Microdrive SR Powerflo-F
Bottom Bracket - Unknown (replaced because the spindle width was too wide for the new crankset)
Front Derailleur - Suntour FD-XR15

After:
Crankset - Shimano Alivio FC-M410
Bottom Bracket - Shimano BB-UN26 68x113 (not E or K)
Front Derailleur - Same/unchanged

Am I expecting too much precision in the measurements or is something really wrong? Is my front derailleur simply incompatible with the new parts? Any help would be greatly appreciated.