1. You're using speculation about the limits of Trek technology here. It doesn't fit how you
think it should
be. Nothing outside your imposed limitations precludes the possibility that they could do it.
2. No, it's bright red booster streaks shooting out the rear of the nacelles, like someone did it with a red marker pen.
3. Dude, it's an amoeba, in space, that's going to eat the galaxy. Again, entirely your speculation.
4. I still don't see why you can suspend disbelief for what came before but not now. Look at the videos in my sig - why is Voyager's warp 9.975 ridiculously slower than TOS' warp 8.4? Because they moved the goalposts.
Maybe I'm just so used to changes I'm numb to it.