Mi is pretty much "my", and "mío" is close to "mine". "Mi aerodeslizador" is correct, and "El mío aerodeslizador" is as awkward as "Mine hovecraft". Source: I'm a native Spanish speaker.
Not a native, but the Spanish version sounds wrong; I've heard em “el mio” used as a noun phrase , but not as a modifier for another noun, so “El mio aerodeslizador” sounds awkward. But maybe it's okay.
This sounds extremely stilted and unnatural. If you really wanted to emphasize it was your hovercraft, you’d say “mon aéroglisseur à moi est plein d’anguilles” but even then it sounds heavy handed.
Not really. "Mi aerodeslizador está lleno de anguilas" is correct and the standard one. We can say "El mío está lleno de anguilas" when the noun (anguila) is implicit by context.
The-my-hovercraft