You have more than enough space on 2 crossbars for all the skills you will need for every job and still have around 8+ slots left over. Go to config and under Hotbar customization uncheck every bar that you aren't currently using for battle, and you can use those extra bars for stuff like mounts/items etc without worrying about cycling to them on accident. You just have to be smart with your skill placement. For example, I have Cure / Cure II in a specific spot on my main bar, and swapping to the 2nd bar has Medica and Medica II in the exact same spot so pretty much pushing R1 in that case is "Turn on AOE".

This is a little bit easier on PC though I will admit. I have a small vertical hotbar i stuck next to my chat log that I stuck the longer-cooldown abilities on so I can see their recast times without being on my 2nd bar. I don't know if the PS3 version can do that.