I agree with your suggestions, Luca.
I'd like to add a few things I've noticed re: the staking experience so far. Figured this would be the best place to add these comments.
I'm currently farming HDX through my DOT position. I claimed my rewards this morning from my DOT position, and added the farmed HDX to my staked-HDX position. This zero'd my accumulated rewards in the staking dashboard. I did not attempt to claim my staking rewards; only my DOT-farming rewards. In my opinion, users shouldn't lose their accumulated rewards for increasing their staked position. Removing stake, I can understand why accumulated rewards would be slashed. Something to consider.
The "rewards boost" meter, as it currently stands, is a black box in my opinion. I started staking when it first became available, and my rewards boost was at 100% (I have been actively voting for a couple of weeks now). I haven't missed a referendum since, yet my boost is down to ~4%. Voting on the past two referenda has not changed this meter. A more transparent reward boost system would be helpful. Even if it's a small amount of boost per action item, in my opinion, these rewards should accrue with each vote, with perhaps a boost decay that encourages long-term engagement.