Wow, you sound like me with your concerns! I'm newly HOH and by researching here I found that CIC can make you feel clogged, like putting your fingers in the ears constantly.
I have shoulder length thick hair (I'm Asian) and I just got my BTE open fits not even a week ago. I work in a warehouse where I do a lot of lifting, bending over, and basically, a lot of physical work.
So far, my hair (I wear it loose) has not been an issue considering how much I move my head around and have to flip my hair out of the way in order to see while I bend over to lift things.
I wear glasses and they sit on top of my aids. My glasses do not feel loose nor do the aids.
I don't even have issues when changing clothes because I'm used to pulling the fabric OVER and away from my glasses rather than letting them rub up against them. Because I do that, my aids are not affected either.
But if you feel comfortable with CIC, remember this one other thing. My audi told me that the batteries for them will last up to three days. I lucked out with 7 days with the ones I chose.
As for your question about being clearer, my experience has been not only clearer, but a tad louder where I'm am lacking, not where I don't need it. It's more balanced now. As a matter of fact, today while I was watching TV with my husband, I asked him: "Hey out of curiosity, is the volume on the TV lower than I usually watch it at?" And he said: " A LOT lower. You used to have to have it at this." And he cranked the TV up, and put on the surround sound. I have to wave at him to LOWER IT!!!
But if you find that it's too loud for you, your audi can adjust them. Mine was loud on one side and she fixed it for me.
Good luck on your decision and welcome to AllDeaf!