It would help a little if you broke your post down a bit: it's very hard to follow when it's a few hundred words with no punctuation.
OEM unlocking is something you should leave alone if you don't plan on rooting. Turning it on will also factory reset your phone, i.e. delete everything that's on it (it should warn you before doing that!), so if you did plan on using it you should back up anything important first. But the funny thing is that you can see it at all: I'd expect that to be in the "developer options" menu which is hidden unless you enable it, which you can't do by accident. So unless you enabled developer options yourself it's a bit strange that you can see it at all.
For the rest, well "SIM Toolkit" is normal and harmless, so don't worry about that. The "faint white screen" seems to have been addressed in another thread. I'm not sure I follow some of the rest well enough to attempt an answer.