I found this when checking the valves and camshaft today.
The galling is at same side of both intake and exhaust camshafts. Those are not as smooth as the normal ones. I'm really looking forward to your advice, should I worry about that? Thanks in advance.

 

Does appear that it had oil starvation at some point.
I would just use a piece of scotchbrite to buff the scoring off of the cap and cam journal.
Nothing really major.
Also, make sure that the oil passages/squirters are all flowing.

 

Thank you so much for the advice, that's really helpful. I indeed forgot to check for the oil passages in cap.