To answer your questions in order...
No, it is not OK, that is a violation of copyrights (trust me when I say it has been tried)
The franchise you would need to negotiate with to gain rights to stream it would depend on what you plan to stream... Funimation if you plan to stream Case Closed (Basically anything from an NA released DVD), or Shogakukan/YTV/Gosho Aoyama if it is the untouched Japanese R2 DVDs. Though, please note that even in either case, it falls under all party's jurisdiction, and if the other party was not properly notified, they can stop the stream and fine you for breach of their personal copyright. Basically, if you get permission from Funi, YTV and Shokakukan must also be made aware and sign off on it (they usually do if it is centralized to America, but streaming is global so you would have to make it a country limited stream).
As for your final query, no. DCW has had its share of issues in the past with copyright infringement for having the Watch section. I severely doubt they would be so kind the second time around. That is unless you get the proper permission from the copyright holders and make it clear you intend to broadcast it from sites x,y,z and have a portal through the fan site and wiki at DCW, and present the proof of permission to Maurice. Then, and only then, would it be OK for DCW.
That all said, as a former member of a college Anime Club, I will tell you, that Funimation can and will likely say no. How do I know this? We asked this same question because the founder of our club was in Cali, and we requested of them CLOSED streaming rights (as in only he would be able to see the stream) and they said the rights for debuting Anime in a college club did not extend to streaming, nor would they allow it. The PR rep didn't say any specifics, but she said they made it quite clear what the limitations were, and it was only for live public viewing. Perhaps their policies have changed, but considering that they use Hulu and their own private streaming service for select series, I highly doubt they would allow it.
Best,
Kyuu