Is there a roadmap for this project somewhere?
You can see the next step in the aquapaper is "fungibility" (
https://pad.riseup.net/p/r.4b621eb394365e18ecaca54fee540762 )
AQUA is "account based" (like ETH) not "utxo based" (like BTC), so one way would be to use built-in contracts to achieve that but I think a separate layer of transactions could be used instead of beating around the bush.
This may allow more "normal" transactions per second ("normal" meaning fungible non-contract transactions)
And keeping the state db as small as possible.
Classic eth style transactions could continue but would require 21000 gas (as it does now)
Hopefully soon we will have a fungible tx layer, for less than 21000 gas per tx. (which is related to operations per second for spam prevention and incentive to include tx in mined block)