Ps4 – transfer the purchased games to the PS4 by signing in with same PSN account

You can't.

At best you can have both accounts homed on that PS4, download the game from account #1, then logout and play from account #2. But account #1 still needs to be bound to that PS4. If you move account #1 to another PS4 then all of the games it had downloaded will be deactivated and account #2 will no longer be able to play them (you'll get an invalid licensing notice).

Yes, PSN accounts are different to ps4 accounts. You can use your PSN account on as many ps4 user accounts as you like. The ps4 user accounts only contain your game saves, so deleting a ps4 account will not delete the PSN account linked to it or it's subscription. And if your worried, just log onto the other ps4 account with your game saves with your PSN account, no need to delete the new one if your worried.