Information and pictures on root-pruning figs below. Here is a link that might be useful: root-pruning

I'd probably lean towards finding a new spot for it -- but with highs in the 90s, it's not the best time to be moving it. Figs in the ground generally don't need fertilizer, expecially N or any application after late spring, but you might giving that a try. You might want to dig up a few roots to see if they appear normal or whether they have nodules, in which case it might be infected with nematodes (see this thread). Nematodes might explain its poor performance. If infested you might want to stick to potted figs (you'd need to buy a new plant, and use a commercial potting mix, and don't set the pot directly on the soil where the nematodes could migrate up.)

You can grow it in a pot...for a while. Since japanese maples easily adapt to bonsai, they make natural container plants if cared for properly. However, Emperor 1 is a large cultivar with a fairly fast growth rate. If you are to keep it in a pot, you will have to take out the root ball every couple of years and re-pot it. Even then, I doubt it can be contained forever. Secondly, I've seen Emperor 1 growing in nearly full sun here in SC. And there are hundreds of Bloodgoods growing in full sun; my mother has one planted in the middle of the yard with absolutely no shade. Granted they get some leaf burn in August, but they look quite healthy to me. So I would say that if you could find a spot near the house on the north or east side the Emperor should be fine. However, I would wait a few years until it is about 6 ft tall or so before I planted it in the sun. As far as trees that grow fast, I'm not sure I can help you too much there. Most trees that grow fast have weak wood and they end up either splitting or falling on things (and you don't want limbs falling on your Emperor or house).

I have had mixed success with delphiniums. I have one in the small front bed I call the 'teardrop' bed (because of its shape) that was planted as a seedling in spring 2005 when that bed was created. That delphinium has come back every year since and flowers twice - once in late June- early July, and again in September. Others from the same batch of seedlings disappeared in about 5 years. The main difference that I can think of that might account for the success of this one when the others petered out is that this one is planted smack against the concrete paver brick edging, which is on top of a base of compacted limestone screenings, while the others were in the interior of beds, away from a source of lime. I've always heard that you should lime your delphiniums.... I'm not sure exactly what kind of delphinium it is. I grew both Magic Fountains and something called Crystal Springs (which I haven't seen around lately) and I'm not sure which this one is. Both those types are short ones - I didn't want to have to bother with staking! Based on my experience, I'd suggest adding source of lime to the planting hole - e.g. some broken concrete.