I don't know what the distinction will be between Steem Engine tokens and SMTs, but presumably they bear a resemblance to each other and your efforts will pay big dividends at that time.

That's why I needed to change my code massively and created a SteemToken class. So, each token is now a SteemToken (even STEEM, VESTS and SBD) and they all have a unique id, which is build like follows:

Token STEEM

- tokenId     : 'ROOT_STEEM'
- tokenType   : 'ROOT'
- tokenSymbol : 'STEEM'

Token PAL

- tokenId     : 'SE_PAL'
- tokenType   : 'SE'
- tokenSymbol : 'PAL'

If there would come a PAL SMT, the token settings would be:

- tokenId     : 'SMT_PAL'
- tokenType   : 'SMT'
- tokenSymbol : 'PAL'

In this way I can work with tokens all over SteemWorld and have it all in a base class. It's more effort to build it like this, but, as you said, it will pay of in future.

I will come back later to your other points ;)