Questions:
1. What kind of soil should I use? I searched around and it seems like the 5-1-1 mix (pine bark mulch, sphagnum peat moss, perlite + some lime) is a good way to go?
2. What kind of fertilizer should I use? I bought this stuff locally but haven't used any, is it any good?
3. They are in 8x8x6 hexagon plastic containers, should I repot them (remove trees, remove all dirt, prune large roots, put back in 5-1-1 mix, add fertilizer) back into the same containers?
4. Why are the leaves turning yellow on some trees? Do they need fertilizer?
5. Most of the trees are flowering or producing some fruit. a). is this a good time repot? b). is this a normal time to do this or are the trees dying?

Here are pictures and summaries of all the trees. I labeled them T1-T9 so they are easy to reference (ex: T3 is going to die you idiot!)

http://imgur.com/a/AuaOP

Help would be greatly appreciated...

2. Jobe's fruit&citrus fert looks ok. didn't see any micro nutrients listed in the link, but the reviews seem good.

3. the trees look about ready to get bigger pots. but i'd wait till spring. you can repot them if your weather is going to be sunny for a couple days.

4. they could probably use a low dose of fert, especially the meyer and calamondin. i like to use 50% recommended strength.

5. in their natural environment there is no cold weather, just dry seasons and wet seasons. and many of them bloom and fruit twice a year. are you planning to provide artificial lighting? without sufficient light, the fruits will be a burden on your trees.