As far as your R-lipoic goes.... you should be able to take 100mg a day. If you have side effects, you can do it every other day.
But if you just make sure you have a snack in the morning and one before dinner, and one before bedtime, say a small snack.
Some cheese, 1/2 of a protein bar (there are new ones available from Nature Valley now in most stores), or some other protein thing, like Kefir or yogurt, you won't get low. Watch your sugar intake and you'll be less likely to get low. The new Chobani yogurt is quite high in protein for example. You got low on the glucose drink and regular food is much different.

Benfotiamine is safe by all accounts in the studies. I wouldn't worry about it. Same with the acetyl Carnitine. The biggest issue for most, is the cost. You should feel more energy on them all, and have more stamina. I have seen carnitine papers for both hypo and hyper thyroid states so I wouldn't worry about it either.
500mg a day is a good start for the carnitine.