Caps are pretty well balanced the way they are... dmg/cost vs dmg/cost they match up against any of the smaller ships well enough, and have a deal more HP, which is as it should be, it is bigger after all. Also since its more expensive a large focus would be put into armor/shield systems etc rather than raw firepower... because of course if it doesn't live, you lose all that cash, and all that firepower. That also means of course that at least 1/2 of the size increase in turrets is raw armor... don't want your guns going *poof* in the middle of a firefight now do you?
The cap ships in the game make sense as they are. They're designed to be the same thing battleships/destroyers are designed to be in modern warfare. They're not lead attack vessels, they're command centers and bombardment/general support. You don't send your most expensive ship head first into enemy territory. You have many smaller, cheaper ships for that. The changes your talking about would turn them into something they shouldn't be. AKA what they were in Homeworld 2. Because honestly, the amount of small combat ships required to take out a heavy cruiser in HW2 was completely ridiculous. The things had like 10k HP and 6 or 8 sets of turrets that would damn near one shot a frigate, if it didn't actually one shot it. and the frigates were doing similar numerical damage to whats done in Sins :/
Someone also mentioned star wars for massive ships being front line attackers... even in star wars that isn't true. They have several different classes of star destroyers, cruisers, corvettes etc in that universe and the fleets behave in exactly the same fashion I'm describing in this post. The Imperial class star destroyer sits comfortably in the middle of his fleet of fighters/cruisers/corvettes/ smaller star destroyers, and mostly only uses its weapons for planetary bombardment or taking out other capital ships. Because, of course, its the biggest baddest thing in the fleet, hence its the safest thing for the commander to be in, and talented commanders are hard to come by. If the command ship dies, whatever battle operation they're in the middle of is likely to at best turn into an organized retreat unless the odds are ridiculously in their favor in the first place. Of course theres always the chance a support commander could pick right up where the commander left off... but maybe the support commander is some position jockeying nephew of a senator or some such and doesn't have a clue(these things not being uncommon).
All in all, it'd be nice if people on this forum would stop whining about stuff that ain't broken/don't need to be fixed(thats not directed specifically at anyone btw, just an observation about the forums in general, they're beginning to remind me of wow forums, which is to say, at the least, not good). LRMs needed a slight nerf, siege frigates needed a slight nerf. Other than that they need to do something about the unlimited resources from returning armada and maybe cap the number of them you can have and after that theres only minor tweaks at best. The game is fairly well balanced as is, RA just needs caps put in place so its not as overpowering late game, it really makes being anything other than vasari for a large map damn near pointless, and it wouldn't affect SP much, just MP, as AI don't use RA anyways(that I've noticed anyhow)
Sorry for going OT a bit, but well, most of its on topic, and basically the caps are fine as they are... maybe some slight ability tweaking etc, but no major changes are necessary. Simply the fact that there are lots of different complaints about x ship or ability from x race being overpowered is a very good sign for balance. If you want caps that turn everything into swiss cheese in 10 seconds or less, go invest 30 bucks in a copy of Homeworld 2 and get all maybe 50(being optimistic) good hours of gameplay out of it before you become bored and likely never play it again.