Hi Moe,
Thanks for your input here. Yes, I did try to remove all spacers, BB fit nicely and no resistance on the crank when I spin it.
tried to install the new chainring as the same position as the original, which is outside the crank spider that caused the 5mm chain line differences (rear is 45mm) an front is 50mm
The new chainring is straight up without any chainguard on the outside, while the old one there is a chainguard surrounding the teeth, therefore the teeth of old chain ring is positioned inside the chainguard with a space around 5mm as well, therefore, i believe the factory setting is completely aligned
in fact, i tried to put the new chainring inside the crank spider but it is stuck with the frame, especially on the wide tooth.
again the concern is on the spacer if this is a mandatory, I tried to search from web and watch some youtube, parktool, etc.but never specified if we can forgo the spacer, and just install BB without spacer on 68mm
most are following shimano way of hollowtech II