PS4 question regarding having 2 accounts and 2 PS4's

Hi, I was wondering if anyone can help me answer this question

I currently have 1 account tied to my PSN for my PS4 and my boyfriend is thinking of joining the game but does not want his own PSN due to the fact he likes using mine when playing on the PS3 for trophies as he likes to share my trophy list...

So my question is this... If i was to buy another PS4 and buy a new account tied to my PSN/Gamertag, can he log in on the second PS4 console while i'm logged into mine on my primary PS4 as i know the PS4 has rules of primary/secondary console and yet i was wondering if it works on FFXIV, incase i'm not explaining well

PS4 1 = FFXIV login and my account is on service account #2
PS4 2= Would he still be able to log in on the main screen while my account is logged in from first one and go on service account 3? if this makes any sense or will he literally have to have his own PSN and own management account to be able to do this?

Are you going to have 2 Square Enix accounts also or just 1?

From my understanding, you can't have the same Square Enix account logged in on two different machines at once - despite it being on different service accounts. I believe he would need his own PS4, own PSN account, another copy of the game and another subscription.

Yeah I thought that would be the case as never tried logging in on 2 machines with the same SE account