Read the FAQ, have some additional questions

So it sais to never spend diamonds, do you not even spend diamonds for SP 2 times per day to farm? Arena battles to get 20 points?

Also im guessing to have all the higher aptitude fighters in your team, like i have 5 (Mai, Yamazaki, Choi, Kyo, Heavy D).
Currently my team is :
Level 57 Vip3:
Front:
4 Star Shingo-Purple+2
4 Star Yamazaki-Purple+3
5 Star Athena-Purple+3

Back:
4 Star Kyo-Purple+3
4 Star Choi-Purple+3
4 Star Mai-Purple+3
Heavy D is currently getting upgraded (Purple right now), considering swapping Shingo for him and placing Mai in front and Heavy D in back. But more welcome to suggestions.
So just wait for One arm bandit thing and roll the ever living crap out of it for spending diamonds monthly i take it otherwise? No daily diamond usage like SP and stuff? What you recommend to farm fragments? Save for special events or how do you do? Save gold for fragment day? But no daily usage? Or do you skip fragment days altogether?
Also looking for advice on formation and potential swaps down the road if i do get them .
So thanks in advance!

Edit: Fighters i have besides the ones i listed. Vice, Ryo, Daimon, Benimaru, Yuri, Kim, Ralf, Mature, Kensou, Takuma, King , Lucky, Andy