The only item I use consistently is Dark Talisman. Everything else, traps including, I usually forget about. Dark Talisman outlives its usefulness by the time I reach 50 Seduction.
Yeah, I agree - Dark Talisman is key to getting yourself back on track until your Dark or Seduction can give you charm, Deep Kiss, or Eyes of Temptation.
Manipulating character state via stuff like lubrication, buffing or debuffing via various potions, etc definitely outlives its usefulness as you gain utility. As well, as turn order starts mattering, using an item may not deliver bang for the buck you need if your turn never happens due to something the enemy got off first.
Fem Draft has its usefulness, as does Priapus (for farming semen and draining stats), but juggernaut and bewitching do not have any usefulness. Raw Aether has trouble delivering consistent results for me.
I'd like to see the demon juices more consistent with the holy water's effects - holy water on Reyka is pretty useful. Damage/stunchance based upon level of Dark would be nice.
Consumable items are interesting, but items like the simple traps should have some sort of sell value or conversion if you want them to be useful later on, especially if Item Caches aren't going to change.
Speaking of which - how do I open and get the ninja caches? I've never seen a button.
Perhaps Item progression/levels or improvement would help, but I think that any expansion of the item system will require adding features to the GUI to accommodate the expansion and compression of items, states, and data on screen.
As an aside: I've noticed that drain mechanics and reporting as an incubus are not consistent with the mechanics for succubus. Are they working 100% the same?