Grammar with Falcon

OK, quiz time:

What's wrong here? Also, what angle makes it actually correct?

Correct; you never, ever add an apostrophe to make something plural.

The reason this particular case could be argued as correct is because "mini" is short for "miniature." The apostrophe could be indicating a contraction, as in "don't" or "wasn't." It's a stretch, but possible.

Vain, vein, and vane:

Vain comes from the root word, vanity. To do something in vain means to do it for pride in one's own appearance or to glorify yourself. 
She wore more and more makeup in a vain attempt to retain her youthful beauty.
He used The Lord's name in vain. 
You could also use it to describe something unsuccessful:
The Chiefs rallied back from a huge first-half deficit to try and beat the Bills, but their efforts were in vain. (Let's see how that subtle dig plays out. Haha.) 

A vein is a structure which carries blood in the body. It can also describe a deposit of ore in the bedrock.
"Some say I play like I have icewater in my veins. Not so. It is Snapple."
The vein of silver glimmering in the dim light of his headlamp made the miner giddy with excitement.

A vane is a thin or flat, rotating, elevated object that will move in parallel with the wind or flow of liquid, such as a weathervane on a rooftop. 

Advice is a noun. It's the thing you give someone when you are advising him. (Advise is a noun meaning to give advice.)

It looks like Stew Baylor and/or the guys at "the muffler shop in Chino" need to reread my thread:

EDIT: Capitalized Stew's last name. Thanks, Reese!

Apart vs. A part.

I saw one of these words used in place of the other recently. Here's the difference:

Apart is a preposition that means "not together" or "not connected." 
I took the whole engine apart.

A part is a noun referring to a component, segment or piece of a larger whole. 
A part fell off his bike at the worst time.
Godzilla smacked a radio tower on his way past and knocked a part of it off.

I just remembered what I understand to be the hardest tongue twister in the English language. It's a great study in grammar:

The sixth sick sheik's sixth sheep's sick.

It means that the sheep, the sixth one in line, which belongs to the sheik, who is also the sixth one in line and is sick, is sick. 😬

I had to do a little research here, because you made me unsure. It seems "reread" is appropriate, however:

https://www.merriam-webster.com/dictionary/reread

https://www.livewritethrive.com/2014/06/27/prefixes-that-put-you-in-a-fix-with-hyphenation/#:~:text=Let's%20take%20a%20look%20at,and%20underused%2C%20macro%2D%20and%20microeconomics 

"Into what you are diving" is technically correct, as we are not supposed to end sentences with prepositions (words which describe a physical orientation or relationship between things, like toward, above, from, into, etc.) However, so many people have shunned this rule that I feel like it's part of the lexicon to say "diving into" without really violating anything. 

The bigger faux pas here is the word your. Your is a possessive adjective, meaning it describes something that is yours. (Your bike. Your mom.) The sentence inscribed in the stone means to say you're, short for "you are." (Do you know what you are diving into?)
Interestingly enough, the writer could use "your" if the sentence were constructed differently and referencing your tendency to dive into things. For example, "do you know what your diving into the river does to my nerves?" 

Aesthetic can be a noun or an adjective. What usage are you upset about? Any examples?

Aesthetic (N) - Beauty, or a particular type thereof. The early 20th Century aesthetic really appeals to me.
Aesthetic (Adj.) - Of or relating to beauty, attractive. I really like the aesthetic qualities of my YZ250. It looks good.