Good post ...
In the term of scalability NULS is good, success of any blockchain platform not only depends up scalability but also hoe is it useful to create smart contract.
NEO is already there which is known as Etherium of China, Would NULS replace the NEO, Is NULS have that potential?
I think NULS definitely has that potential. Smart contracts are on the test-net already, and will be out in October on the main net.
NEO has some limitations that NULS does not.
The delegated Byzantine fault tolerance system poses problems for NEO, since if just one validator node goes offline, the entire network goes down.
NEO does not support modular chains or pos/pow modules to provide interoperability with other chains and NULS does. This article is a good read for more information: https://medium.com/@Burger_9885/the-new-kid-on-the-blockchain-3-0-scene-nuls-vs-neo-85ef73ac4ac9