Regarding Squad Arena and Fleet Arena: Part Two.

This has been suggested many, many times. It's either beyond CG's ability or desire to implement. 
Most of us would happily trade the payout hour in fleet provided there's a solution similar to what happened with squad arena where the rewards became part of your daily ranking from GAC and most people saw a net increase and a massive quality of life improvement. Previously people could pull in 900 crystals a day from taking 1st in both arenas. No one is doing that now but the average is fairly close with a 50% win rate in GAC, over a period of time. So for most people, a positive change. 
Phasing crystals out of fleet arena needs to be similar (no, not just pushed into a new pay-2-win era arena), and possibly fleet tokens for prestige and zetas. They've made zetas much more plentiful lately but some people still have a major bottleneck. 
But right now, fleet is the only place where spending can't help you win. Once a player unlocks leviathan, or learns to counter it with Exec/Profundity, they can hit first. Any change has to make up for that.  

I would greatly prefer the highest daily ranking method than moving crystals to another game mode. I have never really bothered calculating if my gac crystals equal getting one in the arena every day. I would guess it may not be equal just based on facing 90% whales with tons of r10s and a million datacrons. 

The main reason they won’t change is because of the inevitable release of a new capital ship. No panic spending if you don’t have to have it to maintain arena position. 

Arena certainly is the most toxic part of this game. 

What if you received rewards based on the highest arena rank you achieved at any point during the day?

You're not blowing any minds, this has been proposed for years. CG certainly knows about this idea. CG also doesn't read these forums. You post here to talk to other players, not give feedback to CG. 

That game mode was listed as dying soon in a meathead post for the 10-year anniversary. I'm sure the hold up is figuring out where to move all those store shard only toons to so new players.