It seems very unlikely to just be a suffix ending.

The whole thing is a bit more complex than suffix changes alone especially with more out there titles but generally speaking,

I think you've seen a bit on how the endings would change depending on your relationship to the hearer.

For the latter(addressing people you're speaking about) You would basically never call an acquaintance just by name

For instance, take the name 김영철

If you were on relatively equal social standing, you would generally address 김영철 as 김영철 씨 or 영철 씨

If you wanted to take it a step further in respect, you would replace 씨 with 님

For a senior in age or experience in say the workplace, it would become 선배 but this can be used on its without the name attached.

There are also different words for how you would address different members of the family. Unlike in English, you would basically never call an older brother or sister by their actual name. It's more a generic brother or sister word that changes depending on if the speaker is male or female.

For royalty, there'll be surgery trends for different members of the royalty.

They can be used endearingly to refer to older males/females you are close to.

오빠 can be used somewhat flirtingly/romantically as well