Will main story increase in difficulty from chapter 4 onwards?

Ok so after playing awhile I felt like I was trying too hard to be good at the gameplay but unfortunately I'm wasn't. So I would like to know whether or not the difficulty spike will increase too hard or not. my team rating is 16000 and I really can't be asked to do more shuttle runs, dungeon runs and anacorins( the tougher story boss event). I really love the story and music so I'm hoping to be able to play it casually just for the main story and event stories. If 16000 rating is not enough then unfortunately I will have to quit and enjoy hbr from YouTube whenever story updates.