It sounds all nice and fine that you shouldn't have any fear of disassemblying the phone. There is a catch though. When I had bright spots on the screen on my first FP2 I took it off and put it back on. As many of you know, the first time you take off the screen it is kind of stuck. Apply a little force and it comes off. What happened after I put the screen back on was that the front speaker stopped working properly and, the bright spots stayed the same.
I'm now on my third FP2. The first was sent in twice, once for the speaker and bright spots on the screen,and, once for random reboots. The second was sent in due to random reboots, bright spots on the screen and microphone not working. Now I'm on my third and it is working fine (except a few bright spots on the screen).
I'm not afraid to use a screwdriver. (I replaced the battery, screen and speaker on my old iPhone 4S. And, you need more than just one screwdriver to do that.) I just don't trust the built quality of the FP2. The bright spots are coming back on the screen (well known problem) but, I'm not going to disassemble the phone. I'm too tired sending the phone in. I'd rather wait as long as I can before I do it. And, hopefully I don't need to. I'll just live with the bright spots.
Most likely nothing will happen if I disassemble the phone. I do love the idea of the repairability of FP2. And, hopefully quality control is better now. If or when I really need to, I will take out my #0...