Three currencies: JUST NO. I can’t emphasize this enough. The currency should be one.

I 100% disagree with this. The long-term vesting structure of this system (which I think is critical to making this thing whole thing work) necessitates at least two tokens. The third token (SMD) is to the users' benefit because it allows them to avoid the price volatility of typical cryptocurrencies.

The typical user must only be concerned with two numbers. The amount of Steem Dollars (SMD) they have, and the percentage fraction of the total Steem Power (SP) they own. STEEM is something that the typical user shouldn't be too concerned about. I do think that there might need to be blockchain support in the future to flag SP withdrawals to automatically convert the withdrawn SP into SMD (via the best price available in the internal market), as well as a way to automatically convert (via the internal market) from SMD to vesting SP. That way, the typical user never needs to worry about or hold STEEM, and from their perspective there is only liquid Steem Dollars (SMD) and vested Steem Power (SP fraction).

I more or less agree with your points 2, 3 and 6. And regular users aren't (or at least shouldn't be) expected to read the whitepaper.

Regarding point 4, I believe the editor is planned. Remember, this website is still in beta. So it will come eventually.
To steemit.com devs: please still provide the option for us more advanced users to use raw Markdown even after enabling the WYSIWYG editor.

Regarding point 5 about advertisement:

I think you are mixing up steemit.com, the frontend, with Steem, the blockchain. Steemit, the company, does not pay any users for their content. Any tokens of monetary value being received currently are being issued directly by the blockchain.

Any money made from advertisements on steemit.com would be going to Steemit the company. I suppose they could use that money to pay users based on the statistics from the blockchain (and maybe their own internal page view statistics), but I do not think that they should. If they need the advertising money that badly, they should just use all that revenue to continue providing a great free client experience. Hopefully, they can find other monetization strategies (e.g. clearly marked promotional content like reddit does) other than regular advertising, so that the user continues to have a nice browsing experience.