Define "particle", you are definitely using two definitions of a particle in your post. The hole according to you is both an "imaginary particle" and not a "particle".
Yes. It is an
imaginary particle, not a genuine
particle. The former phrase refers to a phenomenon that acts
as if it were a particle (that is, it's convenient, easy, and mathematically elegant to model it as a particle), but, in fact, is
not a genuine particle (in this case, it's simply the collective behaviour of many, many genuine particles).
The latter phrase refers to actual, genuine particles, like quarks and neutrinos.
It's like classical mechanics: it's convenient and simple to model planets as particles with mass, but that doesn't mean they're actual particles. They're just conglomerates which act
as if they were.
I am pretty sure they are particles, of course they are imaginary particles but they are still particles. I did not need you to explain how the concept is formed I just wanted your opinion on the significance of it. As per earlier... I have read a book on Solid State Physics this one time.
Do you not think that the fact that we can make up particles to explain natural events is slightly weird?
No, since it's not different to making up something called 'wind' to explain why trees go all bendy (there is no continuous fluid, just tiny balls bumping into each other).
Perhaps you're confusing virtual particles with imaginary particles? One are real, but so brief as to be (almost) unimportant, while the other is a convineant (but incorrect) way to think about it.
Yes they are.
Also phonons, virtual photons, etc they are all particles.
What else would you call them?
Phonons aren't particles: they behave as if they are, and it's mathematically simpler to model them as if they are, but they're not. They're conglomerates of particles, but that doesn't make them particles themselves. I'm made of atoms, but I'm not an atom.
Virtual photons, on the other hand,
are real particles. The 'virtual' moniker means they exist for such a short amount of time that they may as well not exist, but they do exist, and they (like all photons) are genuine particles.