1 - Yes, it would definitely be on the blockchain. The code in essence wouldn't change.
2 - SBDP would be everything that SBD was supposed to be as far as functionality on the real (fiat) market goes except for the crypto token side of things as it legally wouldn't be a token.
3 - refer to answer #1.
4 - It would be a "coupon" type of transaction, with one big difference:
The merchant would be able to get something for them, to the full value of the barter.
Secondly, there is nothing stopping non crypto token types of rewards being issued on a blockchain.
Just because the "trend" to date has been such to use blockchain technology to issue and track crypto tokens, there is nothing excluding the tracking of other information. (Already proven by various use cases of blockchain technology)
A smart contract is not needed, as the exchange of points (SBDP) is guaranteed in the existing code. (as described earlier in my previous answer/comment).
I'm lovin' this dialogue, guys. :-)
In a private discussion on the topic, I described it as follows:
Which literally sums it all up!