I'm working on a Space Opera novel featuring a group of aliens that call themselves Species 0001. Here's what you need to know about them:
- They are a species of squid-like aliens that evolved on a water world. Their skin can be practically any color under the sun. They are very small, small enough to be held in the palm of your hand. They also have a beak-like sheath that shelters muscular neuron tendrils. (more on those in a bit)
- They're neural parasites that burrow into the host's neck and wrap their tentacles around the host's spinal cord before unsheathing their neuron tendrils and connecting them to the host's brain and nervous system. Any sentient species large enough to accommodate them and has a brain and a centralized nervous system can become a host.
- They are split between two groups; the Originals/Parasites who completely hijack the host's nervous system and see nothing wrong with their parasitic existence and the Altered/Symbiotes who have resolved to be better and genetically altered themselves so they give their host just as much control over the body as they do. In the former case, the host is fully conscious and effectively trapped in their own body. In the latter case, the host is also conscious, and both the alien and the host can control the body via the nervous system. This allows for multitasking, in which the host types in a code with one hand while the alien uses the other to fend off attackers with a weapon. When conflicting commands are sent, the body simply doesn't follow either until the commands change to not be contradictory.
- The Symbiotes are persecuted by the Parasites on the basis that they "make a mockery of our way of life", and there are about 50 times more Parasites than there are Symbiotes. The Parasites are engaged in a concentrated effort to wipe the Symbiotes out and have forced them into hiding.
- Their society is highly stratified and based on certain abilities some of them have. The peasantry have no ability, the engineers and soldiers can manipulate electromagnetic fields, and the nobility and royalty can manipulate gravitational fields. These powers are fairly weak when the alien is outside the host, but become more powerful when it has implanted itself in a host.
- They are incredibly advanced. Almost everything they make aside from their FTL drives is composed of a collection of billions of nanobots called programmable matter, including their clothes, weapons, and spacefaring vessels. When it comes to weaponry, they use directed plasma weapons that can incapacitate or kill at the user's option in conflict with other species, but the noble class doesn't generally carry those kinds of weapons. When conflicts break out between the noble classes, they use shapeshifting melee weapons composed of programmable matter.
- The parasites are well-traveled, and notorious colonialists, having conquered many different habitable worlds, dominating and feeding off of the planets they conquer. They noticed earth in the 1940s, and have been abducting humans since, implanting some and returning others in order to gauge how we will respond to aliens. They think they have a pretty good idea of how we'll respond now and are preparing for a full-on invasion. Fortunately, they're taking a while to prepare for this; their world domination plans operate on a 'slow and steady wins the race' mindset.
- The symbiotes are also interested in Earth, though for different reasons. Earth is much more advanced than some of the other worlds the aliens have encountered so far and may be able to fend the parasites off if warned.
- Their FTL drive works by creating a 'chasm' in the space-time fabric in front of the ship, then lifting the ship off the space-time fabric for a second, allowing it to 'hop' to the other side of the chasm, thereby crossing HUGE distances without technically breaking the light-speed barrier.
I'd like the novel to be somewhat sci-fi with at least some degree of scientific plausibility, but I don't need to get into a ridiculous level of detail as to physics, biology, evolution and whatnot. Note that in the world, the only planets that support life aren't too far away from earth, and thus aliens often develop along similar lines despite being light-years apart due to convergent evolution.
I'm basically asking if this is all somewhat feasible. If not, I'd like to know what parts are infeasible and how I can make them make more sense.