You've asked 2 questions, which have 2 different answers.
Is "here" needed in "Hi, Bob the Canadian here, let's ..."?
Yes. If you remove it, the middle phrase is incomplete. If written, "Hi, Bob the Canadian, let's ..." seems like the author is speaking to Bob. When spoken, inflection makes the meaning clear, but it's incomplete/broken. The middle, parenthetical phrase is actually an "aside sentence", a whole detour sentence in the middle of the other sentence. "Bob the Canadian" is just a noun, it's just a subject with no verb or object. It's grammatically equivalent to "Hi, turtles, let's ...". The inflection makes it clear the speaker isn't speaking to turtles, but it leaves the audience wondering "What, about turtles?". The phrase/'sentence' "Bob the Canadian" also triggers that "You gave me a noun with nothing else - what's missing?" alert in the listener's mind.
Can you avoid the word "here" by saying something equivalent?
Yes. They could have said "Hi, I'm Bob the Canadian, lets...". In fact, "[name] here" is short for "I'm [name]". Picture a large group of people introducing themselves where you have to keep looking around at whoever is speaking next. If everyone just said their name, it would be so short that you wouldn't have time to see who said it. Also, multiple people would speak over each other, because neither was talking long enough to for the second to hear the first was already speaking, and stop to let them finish. By speaking a bit longer, "Over here, I'm [name]", there's enough time for others to detect someone else is already speaking (so they don't speak or stop speaking), and for everyone to locate them and see who it is that's introducing themselves.
Over time, the following substitutions/equivalencies became part of the language.
- "Over here, I'm [name]"
- --> "I'm [name], over here"
- --> "I'm [name], here"
- --> "[name] here"
You can see in the last one, that "here" is no longer parenthetical, but the whole phrase is one patterned shorthand. That's why the first comment on your question said there's no comma before "here".