Can US/Singapore citizens participate in the ICO?
Denarius is not an ICO. Anyone can participate in mining, staking, or trading. It is an open source cryptocurrency.
if this means it is not ICO
where does the project get the funds to run its project?
what this means is just a coin for mining
ICOs are a scam imo and nothing but false promises. ERC20 tokens are nothing special imo. To make an ERC20 Token (An ICO) it would take someone with no coding knowledge about 5 minutes to make it with 10 lines of Solidity code and $10.
Denarius is a peer-to-peer cryptocurrency based off the original older Bitcoin Core code with modifications based off Novacoin and Stealthcoin and other new features that aren't in other coins or haven't been seen before like Tribus the PoW hashing algorithm, Multisig, USD/BTC Estimated Balances, Market Info, NodeJS Web Wallet, etc. everything about DNR is open source free for the communtiy to use/view/distribute/modify just like Bitcoin or other P2P cryptocurrencies. Denarius like Bitcoin and other cryptos is its own full protocol and network unlike ICOs and tokens. DNR has an JSON RPC API that you can use with the denariusd (Denarius daemon) to create external applications that utilize DNR (which currently there is a ton of use cases, the NodeJS Web Wallet, just being one.)
A project doesn't need funds upfront to run, it just takes someone that has the passion and skills to succeed and stick with it.