The message is
@kristinalustig solved the maze and identified "Finley's breeze" as
@Ewasted translated the Morse Code to
Victory and Bounty are
"that unknown southern land" is
So to find the message
Oh, this is a fabulous puzzle - seemingly impossible to break into at first sight, but then when you make a breakthrough you start to spot more and more little hints as to how to solve the rest of it...
The mixtape is titled:
and its coded tracklist is as follows:
How do we find all of this out? The secret lies in realising that:
Taking the title as an ...
This is a fun little puzzle! As clued by the bottom-most node of the diagram, which features an 'I' in brackets, each node of the pictured graph represents:
Meanwhile, the numbers suggest that:
So how do we annotate the diagram? I would propose that we need to:
But this could involve a whole heap of guesswork, right? WRONG
This means that our final ...
From the hints we can infer that
The first one is easy:
We'll skip the second for now and move on to the third one.
OK, on to number four.
Now let's step back to number two.
Finally, the sentence given in the hint is:
The unique solutions to the 3 puzzles have all been found by @Deusovi (Curve Data & Tapa) and @Retudin (Yin-Yang) - here's how to extract the final message... (See their answers for explanations of the puzzles' individual solutions...)
Overall then, the answer to "What should I do to avoid this from happening again?" is:
Partial answer - Curve Data and Tapa solved, stuck on Yin-Yang
Now look at the section
Some important lemmas for Yin-Yang that it is good to know:
So, let's think about this puzzle in a different way.
And now we can start getting somewhere!
...and this is where I'm stuck.
The rankings from 1 to 10 are:
"Spanish Language is actually #5"
Stack Overflow 
Amateur Radio 
Spanish Language 
Graphic Design 
Science Fiction & Fantasy 
Earth Science 
Thanks to Stiv, who found the details of Biology and Graphic Design.
Let's start with the top right as it's easiest. There are 9 square pictures with red borders that work to generate
This is a
Moving to the top left:
I struggled with this one for a while, but kept coming back to the title. It's all about position. After trying many different things, I came back to one of my earlier thoughts. What if the ...
Partial Answer: At this point, I've spent more time on this than I care to admit, so I leave it to the community to complete the solve. 🙃
I overlaid the images together to reveal:
This provides us with 15 letters:
However, I've been unable to proceed further. Some of the things I've looked into so far (perhaps incorrectly):
I'm also including ...
(Thanks to Stiv and M Oehm in chat and the partial answer, I just came in the end)
Don't let that trick you, though!
Using this revelation to our advantage,
This is better as a comment to the existing answer, as it's more observations that might HELP solve (not an actual solution), but I can't comment yet.
I think @Stiv is on the right track, and have come up with several other names
Here's a partial answer explaining (in detail) what I believe to be the first few steps of the puzzle's solution. However, beyond that point I am as yet unsure how to proceed...
First off, consider the schematic in 3 and the image in 5 together. We can combine these...
It then makes sense to consider clues 1 and 2 together with what we have found.
Currently identifying every pokemon in the grid for all our puzzling friends who haven't memorized all the names, because there are a bunch listed here:
Partial Solve, original solution had errors, I have proposed answers for two of the three questions, but no idea on the third.
If we map the numbers to the squares they lie on, we get the string:
The "A B C D" maps to the following:
On to the questions:
What is the meaning of the black line near the bottom-left corner of the image below?
The word we're looking for is:
Line by Line
"You insist I should take one"
"Ten I shall take as I won."
"Tendencies are like a corpse"
"Fire spreads over entire course."
"Fighting as they found a hole"
"Bamboos grow on land as whole."
"Bamboozling, I take villages"
Wrap-up: The Making Of A Puzzling Easter Egg Hunt
This is not a solution to the puzzle, but provides notes from its poser. This type of answer has been approved by the community.
Caution: This post may contain spoilers.
Cryptic crosswords are not everybody's friend... Around ten years ago they were the kind of puzzle I would skip over in a ...