General Zero

Is this how Zero works? My starting weapons stick with me until the end. I get free cubes in a way (WP and meso). I still have to purchase boss set armor except the weapon, which I have to use time coins for. hmm few questions.. 1. Can I use WP and mesos to cube all of my gear or only my weapons? 2. Do certain skills eventually get replaced by other skills or am I suppose to combo every single skill I unlock? Thx for any insight! and feel free to leave me any useful tips!