Have you even tested some of these things out? The Novalith is by
far the best game ender, far surpassing both the Vasari and Advent counterparts, it certainly is not in need of a buff.
The high health compared to low dps is one of the more unique things about Sins imo. In many games, units can kill eachother in ~10-15 seconds, in sins it can easily take ~100 (this is 1v1, take cobalts for example). As such I hardly see why you are saying the health needs to be
increased. Also, it appears you're saying that cruisers/frigates should be nerfed, and battleships should be buffed. If so, I disagree here as well. I currently think the capital vs frigate balance is quite good, capitals are neccesary for bonuses and helpful in firepower, but frigates are the main source of damage output.
Also, making hardpoints specificly targettable is a bad idea since in a game this large, it would induce obscene amounts of micro (imagine later battles, where there are multiple caps etc) and I don't see how it would affect game play for the better. EAW and EAWFOC both used hard point systems fairly well, but they also had far
far smaller unit caps, so it was more manageable.
I agree with the grabity wells to a certain degree. And as for the defenses, they need to make sure that offense is better than defense, because otherwise games that are already long when offense is dominant will become endless stalemates if the teams are at all comparable.
As for more units, I'll be glad if they add more units, just so long as they add equal numbers to all the factions. I'm sensing you're a TEC player from your post, so I think it's kind of funny that you're only suggesting more ships for the TEC

. As is, I don't see that they are at such a big disatvantage in warships anyway (barring the broken repel ability, and certainly their ships are slightly weaker in general, but they also have the best econamy and as such it is a balancing feature).
Anyway, hope this wall of text helps