Pick the one database you and your team/org have been using so far, so you'd spend close to zero time on database issues. I think it would be better to remove

Pick the one database you and your team/org have been using so far, so you'd spend close to zero time on database issues. I think it would be better to remove as many degrees of freedom as possible, simplify aggressively, and delay decisions you don't have to absolutely make at this stage to allow you to focus on proving what it is you're trying to prove.