Memory Management

In terms of memory if i had lots of objects moving on a level toward the player, would it be cheaper to have 1x1 object move toward the player while off screen and when its on screen swap the 1x1 object with a bigger object with a texture.

My only other thought is to somehow make a system that stores the cords in array and only creates the objects when the player is near those cords and destroys the objects when out of screen.

Every object that exists on the layout will be loaded into memory upon the layout start, unless you manually manage memory. Which isn't recommended unless you're very familiar with the system and really need it for some reason (you shouldn't).

Basically no swapping objects won't make a difference, because the object you are swapping to is already in memory anyway regardless.