1. ^

2. Do you try to fall asleep consciously? This sounds more like a WBTB to me to be honest (waking up in the middle of the night and spending some time reading about lucid dreaming or getting yourself set up for lucid dreaming, then going back to sleep normally). If it's a WBTB, reduce the time you stay awake (even only 10-20 minutes is sometimes good, but you can experiment with this), avoid bright lights and monitors, and in general don't wake yourself up too much. You want to be relaxed and aware, not alert and wide-awake. If you're trying to WILD (waking up and going back to sleep without moving much and without losing awareness to enter a lucid dream from the time you're awake), I highly highly recommend against staying awake for more than 10 minutes maybe, at the most dream journal, use the restroom, and try to get comfortable, otherwise you might wake up too much and will struggle falling back to sleep and going directly into REM. This is only from personal experience, I'm not 100% sure if the true holds the same for everyone, but I don't think anyone purposefully stays up before a WILD and reads about LDing in the process (like I said this sounds more like a WBTB, and WBTB and WILD don't go well together).
Lots of parentheses in that answer, oops.

3. I might be misunderstanding the question, is it that you black out for a split second when you go lucid? I think this may be from something like sudden excitement, or even after a while of it happening you expect it to happen now. When you go lucid, don't think about everything going black, just think about what you want to do and try to stay relaxed and calm--you can be excited, but don't let it dominate your thoughts. Stabilize when you go lucid as well (touching objects in the dreamworld, rubbing your hands, taking in details of the dreamworld, etc.)--this will keep you anchored to the dreamworld.

4. ^