Compatibility problems on the ps4 between different accounts

Hey guys so i have a playstation 4 which i purchased from hong kong. I live in india.

Now Im having some major compatibility problems and confusions. I know that the playstation 4 is region free.

I have 3 psn ids one which is indian, one which is hong kong, one which is american.

I have played all my games on my hong kong id and the saved data cannot be accessed when i login from my american or indian id? Why is that? I have to start from scratch every time unless i continue to play from my hong kong psn id.

I have games with different region codes some are region 2 while some are region 1 and some say all.

So i can't even buy the dlc why is that?

My last concern is that i want my us account to be my main one but i have a free 1 month ps plus code which i got with my ps4 from hong kong , how to redeem that code and can i redeem it from my us account? And also some games on the indian ps store are cheaper than the american one so i can download them from the indian store and use them on american account? Is that possible or will I have issues?

The most important part is the SAVED DATA i share the ps4 with my brother and we play the same games but we both have separate accounts and the sad part is if he advances in the game and saves in his account in my account theres no difference and i have to play from scratch ,WHY IS THAT? Its only for some games though like the last of us while playing lego superheroes i can access his saved data which is so weird.

Please if you could help me as I'm really confused and don't know what to do.

Your time and input will be really appreciated thanks also :)

ok, here are your answers:

- it's strictly psn policy that different users cannot share the same save files, this is not different on ps3 or an xbox one, so you cannot start a game with an account and continue from where you left off on another account, it's the same with trophies, or maybe it is because of the trophies...

- if you have game discs from various regions you can still play them, but you must buy their dlc from their appropriate store (e.g. you have a region 1 game disc, so you have to buy the dlc from us psn store)... why??? because of various tax laws in different regions, pricing policies (with us being the cheapest store), etc...

- psn plus is based on accounts, if you have psn plus on your hong kong account, then you can only play online on that account (as opposed to xbox live, where you only one gold account is sufficient for every user on the console to play online)... why??? because it's psn policy...

- bonus answer: if you activate your ps4 as your primary ps 4 on all accounts, you can play downloaded games offline (sp / campaign to be exact), if your ps4 is not registered as your primary console, then you have to be online (hence that account has to be active and online) to be able to play the sp / campaign of your downloaded games... so no account sharing is recommended between various ps4s...

This one point actually isn't true, but it might have been at one point in time. My entire family plays online on their respective accounts even though they don't have PS+. They can even play PS+ games downloaded on the plus-activated accounts.

You can't. What you need to do is redeem the code on the matching region account. The good news is that if you redeem it all accounts on your system will be able to play online. Make sure to go into settings and make sure every account activates the PS4 as its primary system (it will save you some headaches later).

You can totally buy games from one region store and use them with another region account. The only thing is things can get messy with DLC. For compatibility always buy DLC for a game from the same region store you got the game.

@Articuno76: thanks for the correction, i thought i heard it that way and since i am single and living alone, did not need to test it... no one needed to have psn plus to play online games prior to ps4 as well... :)