1. Not sure what you mean. If you add many objects to a family, you can pick Family member by object name. For example:
System Pick EnemiesFamily by evaluate EnemiesFamily.objectTypeName="ZombieSprite"
2. Try moving the first four events on your screenshot to the bottom of the event sheet. Also, you need to use delta-time, and lerp for smoother scrolling.
So, instead of "Rocket move 5px" use "Rocket move 300*dt pixels"
Instead of "Set scroll X to scrollX+5" use "Set scroll X to lerp(scrollX, scrollX+5, 0.4)"
You can try different values instead of 0.4
1) I'm sorry, to tell the truth I completely forgot about the Family function. I mean I haven't used it yet (even though I've been using Construct for over a year). But I'll still tell you exactly what I wanted to do: The spaceship moves and collides with an object (similar to super mario cubes) so it creates the same object but a little bigger in the center of the screen which should show 1,2 or 3 other objects (which could be any objects, different from each other or the same, at this point one object stays in the center and two move one to the right and one to the left. That is, it should be an animation showing some random objects you got. So I should in a list of 20 possible objects make sure that whatever comes out, if it is the first object it stays in the center, if it is the second it moves slightly to the right, and if it is the third to the left. (to show the player the three objects in series).
I'm trying to figure out how to write events in an easier way, I think I'll solve using "Family"
2) I tried to do exactly as you said but (maybe I had to specify) I would like the screen to move at the same speed as the spacecraft, now it moves slower ...
P.S. I've never used "lerp" and have no idea what that means ...