What's with all this DLC for this game? Can you unlock all that in the game or do you have to buy it? It sounds like it would give you quite an advantage online.
Also, can you transfer your save from the Vita version or do you have to start over again?
No. Level 4/5 Balls/Clubs are DLC only. Level 3 can be bought in-game, but why do that when you can just buy the Level 5 Ball/Clubs to be on par with online? I dunno if they have the ability to turn them off online (yet?) but I'll check later today.
DLC courses and characters are worth it though. Add in the Level 5 Big Magnum Club and maybe the Infinity Ball with Kat and you're nearly maxxing out the range (so like 400 yards) but have to control your weakened impact (from C default to like F?)
Cross-save is no. It's cross-play and cross-buy (DLC ONLY!) though.
However if you already own the portable version you get some lobby parts and a reduced shop discount to make unlocking things faster. AFAIK owning the PS3 version doesn't allow the reverse (shop discount on the portable version). BUT ONLY FOR THE ACCOUNT THAT OWNS THE PORTABLE VERSION. So the same one you're playing the PS3 version with. You also are part of the "VIP" slots for tournaments online so if it gains a full 30/30 you can join with one of the extra 5 slots for that tournament if you hurry.