Selling PS4 & PSN on Non-Primary-PS4 account?

Hi,

I'm looking to sell my PS4 along with some games that are downloaded on to the console to my account. I've been thinking of selling the PS4 with my account as well so that the buyer could get the games on my account as well, but I've heard that that is illegal. also I'd need to get rid of game saves as well.

Another thing I've been thinking of is setting my account as Primary PS4 so that any other accounts could also access the games on my account. But the problem with that is I can't seem to find a way to buy PSN on an account that is not Primary PS4. I assume this is the case because if Primary PS4 has PSN and that is shared with all the other account on the system. I don't know if you can or not because i still have a subscription is PSN on my account.

So...

Is it illegal to sell your PSN account and also is there a way to buy PSN on another account (that doesn't have Primary PS4 enabled) if the PSN subscription on the other account has expired?

Thanks.