Two simple questions about better performance and workflow

Hello.

I have two questions about good Construct 3 practices.

Question 1:

If the app that I'm creating has a sign-in system and account creation etc., or let's say some sort of complexity, is it better to have these systems on separate Layout- and Event Sheet Pages? And let's say after signing in move to another Layout to have less code in the "Event loop" or doesn't it matter too much? (I do not use any handpositioned objects in the layouts.)

Question 2:

Is it better for the performance/workflow to use variables to toggle parts of the Event Sheet or to just put said parts in groups and activate and deactivate them as needed? In the example above that could be the sign in or account creation processes.

Thank you in advance.