Please Remove (or raise) the 10 rank SP cap
Just as the topic title states, I think rank difference cap should be removed or raised. The cap has removed all incentive to fight a mob more than 10 ranks above your character. Even though you can kill such mobs easily, there is no reason to do so. If you're in a party grinding for SP, doing so is actually a detriment since harder mobs take more time but don't reward the effort with more SP.
A lot of the reason that players do not grind on open world mobs much is due to this cap. If it benefited me in any way to fight a r40 mob with a group of r20s over fighting r30 mobs, I'd do so in a heartbeat. This is the number one reason we've all gravitated to leves as the main way to get SP. If we could get SP at a similar rate by grinding on difficult open world mobs as through leve linking, who wouldn't do it?