pretty much what Apollo said.
Design the ship using GY`s sim. Then test it out yourself against the existing ships.
If it slaughters everything, you have made it too powerful, if it dies to alot but excells against something else, your on the right track and my just need to mix up the shield mods/range.
Also remember, if the stats are how you want it, but it`s still performing too good, add in scanner rating. It`s the `filler PR` stat that does practically nothing except balance teh ship by increasing, and decreasing, it`s PR by adjusting it. It`s why most guard ships have so much scanner rating as well as why soem collective/maru ships have scanner rating even though those races cannot explore.
The only thing I was looking into was a neutral ship/range of ships with missile damage. It`s the only damage type that`s not currently in the neutral range. We also have no need for yet ANOTHER strafez ship, adding teh King was bad enough in my opinion. However if you wanted to do it and could make it `work` (have a place in the game thats not already taken by the other strafez ships) I would propose the name Patriarch or something like that.
Neutral class battle ships or bigger would be useless in my opinion also. Especially if they where light class, since the only time people use a Light class ship, it`s 1 turn worth for dummies. They are a horrible class of ships with 1 use, which is done better by every other ship in the game, even fodder. Designing and testing them would be a waste of your time IMO, but feel free to prove me wrong.
Finally, any designed ships you have done, post them here with all the shield, damage mods, scanner rating, hull, range, PR and proposed actual use the ship would have so more people can test. We have alot of capable people that have designed/rebalanced most of teh ships in the game still playing.