From what I learned from a Norwegian class, beklager is for apologies and unnskyld is for excusing oneself from perceived impoliteness. So you say "unnskyld" to get by someone, and "beklager" if you bump into them. I think the translation on this answer should be adjusted for this distinction.
Ah, I see. I hear "ja" stuck onto sentences in norsk quite often but it's not necessarily meant as a literal "yes," nor is it required to use with "unnskyld". You might hear "ja, vær så god" for "please help yourself" but a direct translation of each word wouldn't make sense in English.