DISCLAIMER: I almost exclusively play 1-ticket Phantom Draft events and free Draft tournaments. I sell any pricey cards I get, and as a result the game has already paid for itself. I've played many, many 1 ticket events and have yet to run out of my Starter tickets, so I'm loving my experience with the game. As a result, the following is likely a little biased:

a) Completely devoid of any social features

Regarding lack of spectator features; you could try streaming the game via Steam's built-in broadcasting functionality. That said, adding spectating functionality to all games at all times should be a priority. I agree with your suggestion for better support for league-style tournament systems that allow for odd numbers of players.

b) Virtually no feedback from your opponent

I imagine they were originally going to use Steam chat functionality and cut it after some people expressed concern about the lack of moderation features, which is why there isn't an existing emote system to replace that. This is definitely a feature they need to focus on implementing; either reimplement a basic chat system, or include a robust emote system.

On the topic of seeing your opponent's cursor: it's possible I'm in the minority, but I personally hate the idea that my opponent could see my cursor, or what cards I'm thinking of playing, or worst of all: which cards I'm looking at ( cough MTGA cough ). It just makes me paranoid, and on average makes the experience worse for me.

c) Tournaments are not enough, competitively

"This game desperately needs streamlined competitive game modes."

I'm not really sure what possible solution there could be regarding this, or what you even want. Do you want shorter games? Because that's not realistic for obvious reasons. Or do you just want league-style tournaments that let you play over multiple days rather than one sitting? Because the functionality is there.

e) Monetization

This is the part I am most sympathetic towards. The unfortunate truth is you need a sizeable chunk of excess cash to be competitive at this time. Some of this stems from a somewhat stale competitive environment where everyone needs to (or feels like they need to, which is effectively the same thing) play very similar cards in order to be competitive. The best hope for this in the future is that when new sets release, a greater combination of cards become viable, thus spreading the financial burden of play across a greater number of cards. The cynical part of be believes this still won't solve the core problem, which is that rare heroes represent a disproportionately high level of importance in a deck compared to their availability on the market.