(...)
then for over 12 hours my human was not able to tune them up. at all. there was no option for it. it wasn't even grayed out, it simply did not exist.
That is weird and likely a glitch. My bots have never had a greyed-out tune-up.
the bot in the dungeon is still alive after five days with no maintenance and no electricity. they don't die. yet another lie from EA.
As far as I know, they are NOT supposed to DIE at all! When a bot runs out of power, they shut down and don't turn back on until their power motive is filled. As for the maintenance motive, when that one is empty the bot should malfunction (with some external electricity sparks or smoke visible), but still won't die. They usually self-tuneup before it happens.
so far the only plumbot-related functions of this expansion that work with any reliability are the creation and the plumbot having a job... which would have required a dedicated effort to screw up. the only part of this expansion that has NOT been a disappointment has been the jetpack and hoverboard transportation thingies. and you can't even have them both active at the same time.
please tell me that SOME ONE out there is having better luck with their plumbots.
My household bot (RoBotany Gardener, HandiBot, Competent Cleaner, Efficient, Solar Powered) does her tasks well. Occasionally she needs to be "reminded" to tend the garden, but that's as bad as it gets. When she had the Musical Machine installed along with the rest she'd end up playing music and forgetting other tasks. Now she often stands simply waiting for some task to appear (aka dirty dishes, plants needing tending and such). Occasionally she decided it's needed to scan my Sim, especially when my Sim was asleep. So I locked the bedroom door.
My other home-bot (Efficient, Limitless Learning, Holo Projector, Friendly Functions, Sentience, Solar Powered, Office Drone) needs more "guidance", which is what I expect with a combination of trait chips.
So far it seems that a balance of certain trait chips does work with the desired effects, at least for me. I haven't tried the RoboNanny yet, so maybe that's where a lot of problems you're having stem from.
Good luck and happy Simming!