What ratios of card types are you trying to reach? Have you got a checklist you're referring back to?
I'm aiming for about half terminals and half non-terminals. Investment needs a good number of non-terminals to be worth going for. 3 villages, but I'm counting self-trashing villages and throne rooms as less. No more than 3 deck thinners. Probably no more than 3 remodels. I'm sort of counting Refurbish as a remodel right now. Committee, Gambler, and Dignitary are deck thinning, but I kind of wish I had a stronger trasher. Probably it's not a big deal, especially since there are a fair few Copper-using cards in the set.
EDIT: Also want to gush about your two trasher attacks. I'm in the process of making my own set and it seems so hard to come up with a decent trashing attack, and you've come up with two.
Thanks. Axeman came about because I realized that there were cards that combined each two kinds of attacks (discarder, mucker, junker, trasher), except discarder-trasher. (This was before Sir Michael, mind you.) It seemed to me that the simplest way to do such a card was to have it trash a good card from your hand. Of course, that's an incredibly harsh attack, so I gave the option of gaining a cheaper card in its place. I was then too worried that players would simply use opponents' copies of the card to VP rush at the end of the game. Trash Gold, gain Duchy, etc. So the gained card goes onto your deck. This also nerfs the attack a little more in the earlier parts of the game, and that's good too. I'm skipping a few development steps, but that's the gist of it. I called that card Tax Collector. It cost $6.
It left the set because I was still afraid the attack was too harsh. I had run a solitaire game where I got hit by the Attack every turn (since that could easily happen in a multi-player game. I just couldn't get anywhere. My deck was treading water. I replaced it with a discarder-mucker instead. You can currently still see that version in the OP.
One time when we were playing with Taxman, my wife suggested that I should make a card named "Axeman". I decided to bring the old Attack back and add the "can't buy this if you have no Actions in play" clause from some of Donald's outtakes. I haven't done another stress test on it, so it's possible I'll axe it for the same reason. But I'm hoping that 4 turns of build-up before you get hit by it will be enough to make it workable.
I don't really think of Barrister as a true trasher, since it only trashes Domains. It was originally just a trashing Attack that could steal all Treasure cards (including Domains), but I couldn't make it different enough from existing Thief variants to be interesting. So it is as you see it. I don't really want two harsh trashing attacks in the set, so it works out. I still need to try Domain at $3. I realized recently that at that price it can provide an additional buffer against Axeman, which is cute in game that have both Axeman and Barrister.
So my advice to you is to constrain your design space in some way when designing trashing Attacks (or any cards, really). It can help creativity. That being said, a set doesn't need to have a trashing Attack at all. None of the small sets do, and neither does Prosperity.