First of all, when it comes to fertilizers, it's the ratio of nutrients that's important, not the absolute values. A 10-10-10 formula is the same as a 20-20-20, or a 30-30-30. They'll just have different dilution ratios to achieve the same concentration. Now studies have found that nearly all plants have about a 3:1:2 ratio of N-P-K in their tissues. So, I'd say your fertilizer is very high in phosphorus, and a bit high in potassium. The nitrogen level is actually significantly low in comparison to the other nutrients. I use a 10-3-9 formula on my Phalaenopsis and it blooms just fine. I also fertilize year round. Any plant that is growing requires nutrients. You may get by without feeding, but you'd be increasing the likelihood of deficiencies. So I would continue fertilizing, and think about switching to a lower phosphorus formula in the future. You should be able to mix up batches for later use as long as you clean out the container every so often to eliminate any bacterial/algal growth that may occur with the fertilizer. As for repotting, I'd do it now, and yes, bark would be a good thing to add. I actually avoid using sphagnum moss because it decomposes and compacts too quickly for me.

2 lanterns-turned-planters (I'm calling them "planterns"). First one is going to be a work in progress for quite some time. Hopefully this turns out really well and isn't just a costly experiment. Thanks for letting me share!

About washing the roots, it depends & time will tell =) Often nothing happens, at least that's been my experience until something happened =S I got lazy and only shook off the old soil off the rootball of a plant & planted it in pumice. It took about a month or so, but the plant started showing signs of rot. Yellowing and soft lower leaves. Unpotted and found that not washing the roots was a mistake. Since they're succulents and I caught the symptoms before it was too late, I was able to cut the rotted roots off and re-root the stems. Took all of about 2 weeks for new roots to emerge =D Technically, the soil holds too much water around the rootball, that's why you're switching to gritty mix, right? It's up to you whether you want to wash the soil off the roots now or wait to see if there's a problem. That's the beauty of the gritty mixes, at the first whiff of something not looking right, you can unpot and check it out without harming the plant =D

For plants with half that size pot 3-4 gallon) I just open my hand so a few fingers straddle the stem on the soil surface and just invert the pot and pop the root ball out resting on my hand with the plant upside down. I'm very confident that this plant will not just survive but it will grow very well in the soil providing you can protect it from any cooler weather. Steve, I have been using the double strength Miracle Grow for many years. I purchase it in the large 15 lb. boxes and add 1 1/4 lb to 40 gallons water every time I plant any vegetables with my water-wheel planter. Transplants always need that boost to begin the transition to cooler soil. I guess I should state that their recommended level is one tablespoon per gallon water so just use 2. Don't go overboard.