Basic Fertilization Questions

[HiOrcDen]

I bought some Miracle Gro Orchid Food, recommended by a seller, and also something I had to pick up on short notice.
I want to be sure to follow the instructions correctly. It says 'For Orchids and other indoor acid loving plants' apply 1/4 teaspoon per gallon, and apply. While it says for outdoor plants, a 1 tablespoon over soil, on the same schedule. So would an orchid kept outside, still in a typical mix such as orchid bark, receive any more than the 1/4 teaspoon? Are there different guidelines for Orchids kept in moss, or fiber?

In the long run, am I right to think I'd be better off with a strong organic mix? And one of my sellers suggests they found a great slow release mix that's better than the Miracle Gro they had been using. Are there advantages/disadvantages to slow release?

Finally, this seems tricky, how to know you have watered enough preceding the fertilizer, and not too much so that fertilizer is not absorbed, and then how to know you have thoroughly fertilized your plant, without burning? (especially with inorganic)