Asked in a G+ comment:
How common is it for individuals to own full up dreadnought or super-dreadnought class warships? Am I correct in thinking that individually owned and operated cruiser and frigate class warships are commonplace?
Actually… not very common at all. (Even for corporations and other coadunations, even.)
That’s not a matter of legal restrictions, of course. While there are lots of remarkably illegal things one could do with a personally owned SD or DN (or BB, for that matter), the Empire continues to follow its basic ethical and legal principle that you don’t go around exercising prior restraint on the innocent just because that’s easier than dealing with the guilty, insert opprobrious remarks as appropriate here. It may not quite be the same SD/DN/BB that the Imperial Navy is flying around (given things invented and manufactured internally at BuInnov, and certain timed-exclusivity research and development contracts), but by and large, if you want an SD/DN/BB, Islien Yards and various other Imperial cageworks will be more than happy to sell you one.
The question is more “why would you want one?”
The primary problem is that, per SotF, in addition to being a bloody expensive piece of hardware, a SD/DN/BB is also a bloody specialized piece of hardware. It’s pretty much got one function: counteracting other ships of the plane in the major fleet action battlespace, or dominating the volume in which other such ships aren’t. And to do that, per the implications of NSSS, it doesn’t operate alone: SD/DN/BBs operate in squadrons much of the time, but much more important are their screening elements. They need their associated CC/DD/FF squadrons to counteract the other guys’ CC/DD/FFs, otherwise they get swarmed and destroyed by smaller vessels that can dance circles around them under their guns.
About all you can practically do with an SD/DN/BB is fleet actions, for which you also need a supporting fleet. This is a very limited set of applications for anyone except “navies” and “seriously top-end mercenary groups”. If you had a personal one, you might be able to spend a few months playing “Send me tribute and attractive tribute-sack carriers” with underdeveloped hicksworld colonies before an actual naval force crushes you like a bug, but that’s about it. (Assuming you can get to them, because many polities don’t have the Empire’s relaxed approach to privately owned capital ships.)
All of which is to say: you can have one, but by the time you pay for it, and the crewing of it, and maintenance and resupply for it, and the eye-watering amount your tort insurer wants to cover it – well, what you have is a giant hole in space that you pour money into, and almost no applications for the thing to make the money back. Even by the standards of hilariously rich people, and even if you were deeply invested in status games – which people *there* by and large aren’t – there are better status symbols, y’know?
(Which, I rush to emphasize, by no means denies the existence of the Eldraeverse equivalent of Booster Terrik and his Errant Venture – it’s just that all the problems he had with it, with the exception of being leaned on by the New Republic, will also afflict his analog.)
On the other hand, you’re absolutely correct that there are more’n a few privately owned CCs and FFs around (both individual and corporate), although not necessarily intended in a primarily-warship role, just a warship-capability role. A FF makes for an expensive yacht/courier/etc., but if you’re in the habit of visiting the bad parts of the galaxy and/or getting into fights when you get there, it’s probably a worthwhile investment. Likewise, the design parameters for a CC include operating solo and being a heavily customizable part of the design-space – most of the specialized variant starships within and even without the IN tend to be built off a CC base – so if you have a task to do that also requires a decent helping of ass-kicking ability, starting with a CC spaceframe is a good move.
Neither of them is exactly ubiquitous – because most people don’t have practical reasons for investing in the military-grade stuff – but they’re certainly common enough that no-one would be surprised by seeing one or hearing that so-and-so had one in dock somewhere, belike.
More generally: if the imperial military and major mercs were to disappear tomorrow, how much military hardware would still be around and what would the force distribution look like?
Quite a lot, although biased fairly heavily towards the light end. By the time you’ve added together the Watch Constabulary (who use basically the same light infantry, light cavalry, and light starships as the Navy, just with a different paint job and software loadout), corporate and non-corporate branch security forces, military recreationists and other hoplo-hobbyists, huscarles, etc., etc., etc., together, it’s a lot.
If you allow keeping the 95% of the Home Guard that is citizen-shareholder militia and only delete the 5% that’s the central military cadre, it’s a whole lot.
And then, if you first bear in mind that arms manufacturers thereabouts don’t see any dichotomy between products for the military market and products for the civilian market (which is almost entirely created by regulatory requirements *here*), and then, second, bear in mind just how much equivalent-functionality hardware is out there in the form of, say, hazmat-protection “armor” and construction worker’s “exosuits” that don’t take much refactoring, and then third, consider that the one thing that is guaranteed to be around just about every corner is a cornucopia machine…
…well, I’m not saying that losing the heavy stuff wouldn’t hurt, in many ways, and there would be many complaints about the inconvenience of it all, but one would still have to be the heir to the throne of the kingdom of idiots to try your hand at invading that.