This is a big proposal that clearly requires a lot of effort. Thank you for that!
As a recently joined DAO delegate myself (together with a full-time researcher) it can still be overwhelming to keep up to date with all that’s happening in the DAO.
So this proposal could bring stability to Arbitrum and encourage more user participation in the ecosystem.
The breakdown into 5 roles makes sense, especially with the reduced minimum hours to optimize costs while still delivering outputs 
As for the retroactive funding, I’m think it’s right to request funds for work already done before. I understand that developing a large initiative like this takes a huge amount of effort and this could be a breakout initiative for next year, so for now I’ll vote "For with retroactive.”