Its probably white fly, and if I'm not mistaken the show up when the soil is soggy. You need to treat the flies, but stop watering so much. Once a week is plenty. On that note,the soil in the pot looks dark and organic, which is not good for succulents. A far better soil is a commercial cactus and succulent soil mixed with 50% pumice or perlite. And I think its an echivera.

Perhaps you are thinking of Fungus gnats? Adults are tiny, annoying flies. They don't harm the plant but their larvae will.

Rob is correct that you need to make sure the soil is not constantly wet; make sure there isn't much organic matter in it, and no standing water around - these are conditions they like.

Your plant is loosing it's color since it doesn't get enough light. It is also etiolating = stretching, growing long and thin stem, and the leaves are far apart for the same reason.

Yes, fungus gnats most likely. Good advice above.

Whitefly are horrible insects that can do a lot of damage while also growing resistant to pesticides extremely quickly since they reproduce so fast. I never have had them and never want to!