Sorry I'm asking so many questions but the more I read on the forum the more questions I have. I have 3 important ones with pictures.

1. Does anyone know what my meyer lemon is missing and what this stuff on my leaves is? In one of these pictures there is a picture of a small bug. I only found 2 of these bugs and could flick them off that back of the leaf. They are very small and hard to even tell they are a bug unless you look reallly really close. The tree came like this a couple of weeks ago from the nursery. I am going to buy some epsom salts tommorrow (sorry for the poor spelling)

2. Also my the fruit on my kamquat is turning from orange to yellow. Is that from not watering it enough, I know I am not overwatering but I might be underwatering or does it need something else?

3. I plan to repot today or tommorrow. I think my trees need it. I would like to know a good basic potting mix. I have read quite a bit and Millet and others have talked about CHC with perilite, turface , and regular potting soil and other things. I have decided to find a type of bark, potting soil and well I'm not sure what else to choose. What is CHC is sounds like a good choice I was going to treat it like Millet suggested in another forum. My temp here ranges from below zero in the winter to 105 in the summer and summer is coming soon. Should I put my trees in diffrent pots than the black ones from the nursery?
For nutrients I am using 1 tbls of vinager in 1 gal water and I am using miracid for fertilizer already.

Old leaf miner damage.

As Lazz points out above, the 1st, 3rd and 4th leaf pictures are old damage by citrus leaf miners. The other yellow leaf could be from fertilizer, watering, or an assortment of other reasons, but unless you see it on more than one leave, I would not give it much concern. As you live in Cedar City, Utah, the leaf miner damage must have happened before you purchased the tree. I don't believe citrus leaf miners can live in Cedar City. I normally stop in Cedar city for gas and also frequently drive over an get a hamburger. I believe Karl Mecklenburg (former Denver Bronco football player) came from Cedar city. CHC is Coconut Husk Chips, which are commonly use in Orchid culture, and are becoming popular with container citrus growers. Whatever medium you choose just be sure it has excellent drainage, and good soil aeration. For northern growers that must grow their trees as container trees, the most important (number one) concern for a healthy tree is always the trees root system. Why are you using vinegar? If you are using it to acidify the soil, vinegar being a organic acid it life in the soil is extremely short. Take care. - Millet (1,365-)