Q:

Making a PSN account on a friend's Playstation 4

My question is kinda simple but I can't find a similar case on the web.
I am borrowing a friend's PS4 and don't own a PS4. I also don't have and never have had a PSN account.
I've created like a local profile on PS4 and have played quite a lot on it. 
Now I would like to create a PSN account to save my trophies and cloud saves if it's possible and maybe later buy my own PS4 and log in with my PSN account.

Will it in any way hurt or damage my friend's PS4 profile or PSN account,
if I create a PSN account on his PS4 and login with it ?
Like with the only one primary PS4 per account. This would make both my friend's and mine account use the same PS4 as the primary. Will it do something wrong to his account or PS4 ?

A:

For primary accounts on a console there can only be one per account. When you make a new PSN account on his console this will make that PS4 be your primary console (I believe it does this for brand new accounts). You will not be able to do cloud saves without paying for playstation plus, but your trophies will be saved to the cloud by default since it is related to your PSN account. To answer your questions directly:

This will not damage your friends PSN account.
This will not do anything wrong to his account or PS4, though when you get your own PS4 you will need to deactivate your account as primary on your friend's PS4 (if by chance it is primary) or you will not have access to any purchases you may have made or will make.

