The ninjamine will always be the dark cloud that hangs over Steem, and will hinder growth and perception for years to come. Unfortunately, it is what it is, and as I mentioned, I'm just extrapolating from the bad hand we have been dealt. I'd like to see a fork (not Steem) by some people which addresses these issues though, and see how that goes.
We'll have to agree to disagree on SBD. As you can see in the comments below and elsewhere, it's largely unpopular, and at the very least needs an overhaul. If mechanisms were devised for SBD to hold roughly $1 without exerting a significant debt burden and consequently inflation on STEEM, I'd be happy for it to stay.
Yes, #3 is pretty straightforward. I understand there's differing opinion among witnesses (as with SBD), but hopefully perceptions will align over time.
I've supported Burnpost since day one. It definitely signals for significant changes so burnposts are no longer required.
It doesn't, up until now, signal much because its participation has been low (1-2% of reward pool). Even back when SBD was radically overvalued meaning that 1 STEEM sent to burnpost in liquid rewards would buy 10-15 STEEM from the market and then reduce inflation by 10-15 STEEM, it still only had very small participation (albeit slightly higher than when that clear 'bonus' went away).
Possibly the EIP changes making direct milking more difficult will increase participation and build stronger signal to lower inflation. I have noticed some of the vote-selling bots starting to use their extra vote power on it. Maybe if you can't just outright reward yourself, it then becomes more attractive as a second choice to at least help protect the value of your investment.
I'd say 1%-2% of the reward pool for effectively burning one's own curation rewards is quite significant.
You can still get some curation rewards for burnpost, although they will often be poor, and likely will get worse over time.