hi there - so i've been lurking to wait for more info and pics of your plants. actually, they seem to look pretty good, what are the indicators that they're not doing well - the fact that they're not growing quickly? generally succulents will be slow growers, especially if they're not getting a lot of sunlight. your herbs are growing quickly because a) herbs (and it seems lots of leafy plants) grow quickly in general and b) they're outside getting a lot of sun. just reiterating what everyone else has said, but i definitely would not water them at the same rate as the herbs. Also, the burrito tail, and any succulent that has particularly fat and juicy leaves will need less water than other succulents (elephant snack) because they are retaining a lot more water in those plump leaves. finally, in general, while the container size might not seem large, I think people are just wondering about the soil ratio - basically, if there is too much soil (due to not enough of a gritty mix, or due to a too-large pot and etc), then water stays in there longer than it takes for the roots to take them in, which then causes root rot. One thing about the pots (which are super cute btw) is that even though the pots have drainage holes, the way they are constructed (tall with a smaller opening) means less top surface area, which means slower rate of moisture evaporation, and so the soil will stay wetter for longer. anyway, all this just to say: water them a little less, like maybe just once every 2 weeks, and the watering doesn't have to be a total drench. if water is not coming out of the hole, that's ok! definitely if you can "let them out" and sit in the sun sometimes, i am sure they'd appreciate that. see how that goes before you go crazy trying to mix up the soil and disturb your plants. definitely if you figure out how to create your gritty mix then by all means do, but for now, yeah, less water and a some more sun. also, sorry for being wordy - not trying to be too technical, but i just tend to like understanding reasons for why things work the way they do.

Loss of lower leaves is normal - as plants grow new leaves, they get rid of the old ones. It's not a lack of minerals so much as a natural fact. As to your etiolation problem, you've probably guessed that you need to increase your light levels. Do a search on this forum for supplemental lighting (I'd tell you, but I can't tell you much as I don't use them). Lastly, most Crassulaceae (the family your Echeverias are in) are opportunistic growers - if it's warm, lit and there's some water they're going to grow, so I'd be careful about classifying your Echs as summer growers.

OTOH............................if your soil mix has no problems with drainage whatsoever, a small amount of castings properly mixed into the mix won't hurt. I know many plants benefit from organic amendments, but it is as stella cites, two different worlds in growing in / out of pot. Many plants don't mind steer manure, even if they're potted, as long as the mix is extremely porous - this is particularly true with a number of caudiciform plants, like Cyphostemma.

I use those same bulbs with a 13 in clamp light (similar to the one above) with a dual socket adapter in it. I think it helps significantly, but I probably need to get another to cover more area. I keep my black Prince and others prone to etiolation under it, probably about 4 inches from the bulbs. I do rotate other plants under it too. With that said, on sunny days this room also stays pretty bright (photo taken on a cloudy day)also somewhere around here I posted a picture of my black Prince prior to getting it into good light and an after. Went from light green to dark purple. Took several weeks and then it was like it changed over night.