Riley, you do ask a lot of things and multiple times. There is only one answer and it is simple. Buy them and experiment. No one knows what ears you have.
From the 2 years of owning ie800 I can only say that I used them both shallow and deep insertion, both over the ear and straight down, both amped and unamped and everything in between. Except for IEMs that are too big to deep insert, you can use an IEM as you like. Ie800 can totally be used with deep insertion if using small tips and will sound great. IT can also be used with shallow insertion with medium or big tips and it will sound great. It all depends on your ear shape and that is something you only know. I couldn't use certain IEMs due to my ears making them uncomfortable (ie80 would fall out every now and then, no solution at all to this, the tubes were too big to stay in the ears) and I was able to use ie800 regardless of fit.
Ie800 does have a fit that you need to get used to. I do usually recommend only buying things you can test. I found Oppo PM-1 to sound nice, Senn HD600 to sound nice, but I disliked Senn HD650 albeit some people feel that HD600 and HD650 are very similar..
Hard to say how you will feel about things. Try to end the despair and enjoy what you have right now. Always enjoy and be grateful for what you own - nothing will make you happy if the happiness doesn't come from the inside.