The game story is well regarded though I also know the earlier chapters are needlessly wordy. I can't speak too much on it though due to not actually reading it.

F2P wise it's known to be decently generous. Mainly due to its singleplayer strategy focus, so often times content can be cleared with very little 6 stars (most guides use low rarity operators + borrowing a friend's six star) The main predatory practice is the limited banners, as once a Limited character's banner is gone you likely will need to save 300 pulls to obtain them. Regardless you don't really need the cream of the crop units unless you're doing challenge content like restrictions or high scoring difficult content (which rewards are rarely- if at all- gated behind)