ps vita

Hi people, i want to play my ps4 remotely with my Vita, but I have a few questions: 1- Is it possible to use remote play between a hacked PS Vita and a non-hacked PS4 ? I saw in some places that both systems must be updated to remote play, is that true ? 2- Do the two consoles have to be logged...

I noticed you can't buy digital games for these systems anymore. I can't even view my purchases. Is there an action to try to preserve the content before you can't download anymore? Some group somewhere? I've never been able to contribute before, but I can now and I don't know where to look.