We are veering off topic here. There is a lot of your points I could argue based on my experience as both a player and dev, but it would serve no purpose to hold such debate here. Though I will gladly discuss it directly with you on discord.
For now it suffices to say that the Dev team will consider the issue of ranged touch attacks.
I've made a list of the cleric spells that are going to be affected by a possible change on zen archery (i may have missed some, but i think not)
- negative energy ray: it's good and satisfying when it hits, but at max power it usually hits around 15/17 dmg, 5d6 at lvl 9 aren't the scariest attack, the strong thing about the negative energy ray is that it can be spammed.
- slashing darkness: looks great, doesn't hit super hard, from 5d8 and 5d6 there's not a great jump, it's just slightly stronger than a negative energy ray, slightly
-Searing light: the same as slashign darkness, there's the 10d6 against undeads but they have the saving throw to half the dmg... so it's basically a single target fireball, that may deal no dmg in case it misses (it should be ok for it to hit more often)
-Evil Domain Enervation: now, this may be the problem it's by far the strongest attack on the list, it's going to be a lvl 5 spell (bcs that's when domain gives it), this MAY alter the game balance, yet i don't think many people would spam enervation: it's very dangerous only if you use it mmore than once to focus down one target wich means you'll usually be using a lot of power to take down just one enemy (that's kinda the point for a ray build), it's kinda hard to take down something with negative levels but it's direct dmg on saving throws so you can cast one or two enervations on the target and then get close and try to finish him with slay living, it's still going to be 3 lvl 5 slots wich means you are renouncing to quite powerful buffs
- Lucent Lance, this may be doing some good dmg... but only in daylight, i still don't think it would be overpowered
-Energy Drain: same as enervation, with the addition that they work very well toghether
i think the biggest problem could be the negative levels, but as i said you would be using a lot of resources to take one single target down, it can be worth or not, it depends on the situation, it's not a good strategy for every scenario. It shouldn't be game changing nor game breaking it would just open the door to different strategies and different clerics.
For the druids i think there's only:
- Quillfire: it's nice, but totally not gamebraking, little damage and there's a saving throw on the poison
- Flame Lash: it's good, but it's just a bit stronger than the negative energy ray, it can become spammable but it won't do TONS of dmg
- Fire Seeds: Now, this one will do a lot of fire dmg (i am surprised they put THIS spell in the game), but you can give the acorn bombs to other characters with high BAB, so i don't think that zen archery would make this spell cause more problems than those it already can.
these are my thoughts, i hope they can help