BO3 - Moving around more fluently

The thing you're talking about with sliding further it's called G Sliding. Search it on YouTube for a tutorial on how to do it.

The advantage always pulls back to your gun skill, if you can't win a gunfight then nothing is going to help you. Using the Thrust Movement to your advantage is a good idea; chaining wall runs, jumpshots, dropshots (not so much), and again, gun skill. Using your weapons and specialists to your advabntage will also be a good idea. OP weapons like the VMP will always win gunfights if you have the skill necessary.