Yield is determined by the total amount of DEV tokens being staked and the amount of assets onboarded. Yield lowers when DEV staked grow and raises when more assets are onboarded.
Yes, every project has the same yield to encourage supporters to support the projects that they believe are most valuable to them.
There's no lockup. Users can withdraw their stake and rewards at anytime.
Yes, there are additional benefits to staking besides earning yield. Valuable projects may have an impact on your daily experience and the ecosystem's capabilities. In the future, Dev Protocol may develop an additional application for projects to offer perks to their supporters.