Explain to Me the Aether Raids Changes

I can't answer what changes were made, but the reason you can do so few now is because each aether raid, the cost to perform another goes up, presumably to reset each season. You get one free one every day, but I don't know if that counts towards raising the cost. From what I've gathered, you want to make it a point of destroying both of the defender's aether resources every map, because it seems like each time you do this, the amount of aether you gain from them goes up, too(though perhaps not every time, but it's been rising for me.)

4 changes-
1) Adjusted rewards
A: Unsure how they were adjusted, but shouldn't be anything about it.
2) Adjusted Healing Tower (O) Description
A: made it more clear
3) Equation for calculating the amount of aether consumed
A: This change was made since it was determined if you lose a single unit in your FIRST match (which is free), your follow up matches would cost LESS than they should. So this meant to be in the top players, you'd throw a unit in the first match, and play perfectly to get the high score. This equation was adjusted so this is not the case.
4) Replays
A: Now fixed

RE: "I noticed today I got a free Raid, but due to cost, I could only do one afterward."
A: First match is ALWAYS free every day you play. Amount afterwards depends how much you have left over. 50 replenishes each day, so if you played 3 times, you are likely closer to 0 aether. If you are only playing twice, it means you have like 10-20 some aether that is not used due to the matches requiring more aether. This is by design, when you move up tiers, matches cost more so you end up having to play less matches. When you are destroying enemy aether structures, you increase your chance to have additional match for the day. It all depends how much each match costs, and how much is 'unspent' at the end of the day, which carries to the next day. When the season starts, each match will only cost like minimal aether, plus you started with a full batch of 100 aether. Now if you've upgraded your aether structure, next season you will start with 150 or 200 depending on your upgraded level.

RE: "I also dropped from 8k rank to 44k. I'm not saying I shouldn't have, but is that due to some changes? The lowest I had been was 12k, so the sudden spike really surprised me."
A: What matters is you hit the 100 life (aka score) for every match and hit both aether structures. Your rank will always adjust depending on if you are securing perfect matches or not. In future seasons, you will drop when defense losses will make you lose lift. It also depends how players are using up aether. Some may only do the free match and carry over the 50 for the next day and have 100 available + any leftover + any earned in matches. Seeing as the season ends in 2 days, it explains a drastic change in the rankings. As long as you don't let your aether cap, it is okay to play this way.

Short answer:

Rewards: The previous rewards for rank 1-1000 are now given to 1-3000. So, more more people get "the good stuff".

Aether cost formula - The only thing that changed was a small fix that allowed people that lost 1 unit on the first day of a season to be able to get an higher score than someone who had 100% perfect scores. That's it, it is virtually the same otherwise.