The small bug left and down of the silky item, looks like scale. Not sure whether the silky is a good bug nest or bad, perhaps someone else can comment on that. Or maybe take a more close up.

Have you fertilized and with what?

Last fertilized them with a 5 1 3 liquid mix about 3 weeks ago.

The curled leaves on the satsuma makes me think it might be under watered. How do you check to see if it needs watering? How often do you water?

Both of them get watered about once a week, give or take a few days since its still pretty cool over here. I check the soil moisture by sticking a finger a few inches into the mix.

I don't think it's under watering, because when I got the plant last summer and it started looking sad, my initial reaction was to water it every 3 days, or 2 days when it was really hot. It didn't make much of a difference. Fertilizing made the leaves turn green again, but they never uncurled much no matter what.

This is how it looked about a week after I bought it

Move it to a spot to reduce the sun exposure a little bit, and wind if the air is cold or not very moist. I have found out water stress can still occur in young plants even if the soil is kept well watered. It's simply too much water evaporating from the leaves, more than the little plant can handle.