I have a few thoughts on the transactional aspects, but would love some feedback:
1) Yes, we can easily implement a MAST to MAST via exchanges anonymous transaction mechanism.
2) We could build more complex options for anonymous transactions that could send a specific amount to a receiver. The sender would need to send enough to cover any temporary price fluctuations, but we could build that into the price estimate to tell you to send X+Y coins (X coins, plus Y coins as a price buffer). Then we could send "change" to the sender for any overage (in a separately timed/sent transaction of course to avoid linking the sender and receiver in any form).
3) Is there actually a serious impact on practical anonymity if you use CoinRecycler, have your coins sent to a new MAST address in a wallet you control, and then send them to a recipient from your wallet?
I think BTC should be added to CoinRecycler, it would be really usefull for a lot a people to buy coins "offline". I mean, once you can get your BTC traded for MAST directly from the wallet you don't even need to put a buy order on an exchange, you don't need any online accounts... this is big.
EDIT: MAST to MAST anonymous transaction mechanism via exchange is also something great.
EDIT2: here are 3 more logos from Nebulas
https://i.imgur.com/h3kS0V9.png
https://i.imgur.com/43fpCT0.png
https://i.imgur.com/IkuQjiV.png