Questions about ps4 upgrade campaign & transfering ps3 save data

I have several questions about the ps3>ps4 upgrade campaign.
1.) Do I have to finish the upgrade process and download the ps4 version on the ps4 before I hit the "transfer character data ps3 -> ps4" button in the corner of the launcher on my ps3? Or will it be too late to transfer my data that way since once I upgrade to ps4 I won't have a ps3 licence for ffxiv anymore? (not sure if a ps3 game license is required to upload ps3 save data from ps3 to the server)

2.) If I am able to hit the button & transfer the character data before I complete the upgrade to ps4, will I be able to play the ps3 version normally until I'm finally able to upgrade? (don't have a ps4 at the moment because I can't afford it until my birthday in may)

The short answer is no, you will not be able to play on your ps3 at that point. This is a one-way upgrade, once you do it you cannot go back. But since the ps3 support is stopping when 4.0 hits, you're going to have to upgrade one way or another.

If your PC can handle it (And it can if you don't have a potato), I would just pick up the PC version of the game. I've seen it for like 20.00 for both the game and the expac with I think a free month on top. Add the codes to your account, and then...you will have done the thing.