The second one there is a pretty creative combo. Gem isn't particularly known for dealing high damage, especially in close quarters, but that particular string of attacks seems pretty situational.
Aside from slightly more damage, his new close C is useful because it moves him forward just slightly allowing the latter half of your second combo.
His far C isn't that great admittedly. I've used it as a decent anti air from time to time though. Although usually its not enough to dissuade people from recklessly jumping at you. His 3A and 3B come in handy here.
3A, I've found to be one of gem's greatest tools. Not only can it combo into cl.C from max distance, but it's also really good for messing up jump in attempts. You move fast and low to the ground allow you to pass under most opponents and either escape or punish from behind them.
3B can be used if you anticipate a jump though can be risky. I use it mostly as close up shenanigans. Useful for avoiding grab attempts or sweeps and puts you right in there face for a throw or something. It places you in the air almost immediately (faster than a throw) and has no landing frames. Used in conjunction with 3A, 3C, and 4C, it allows gem to really dance around his opponent.