I would recommend that one lunch or dinner is spent at les Vendanges (porte d'Orléans) where you get truly awesome food for 35€ (25 if you go for the two courses menu, which I really should do if I don't exercise more until then).

when i lived in Tokyo, occasionally i attended the Tokyo Pecha Kucha Nights:

What is Pecha Kucha Night?

Each presenter is allowed 20 images, each shown for 20 seconds each - giving 6 minutes 40 seconds of fame before the next presenter is up. This keeps presentations concise, the interest level up, and gives more people the chance to show.

how about have a EuroTrib Pecha Kucha night (or day) at the Paris meet-up?  we can tweak the requirements (e.g. images optional, different time limits, etc.) as we want, of course.  the main idea is to have a format to elicit interesting talks and discussions in a creative fashion.

(Pecha Kucha nights happen in cities around the world.  if you want to attend one, you can check if your city has them on their website: Pecha Kucha Cities)

As for Friday, we could consider visiting the Pere Lachaise cemetary, with a dinner in the Chinatown of the 20th arondissement afterwards. We considered doing that last year but changed our plans for reasons I don't recall, although we certainly had a great dinner in the quartier Mouffetard.

If this is going to be an East Paris centered meetup, I'd recommend what is probably the least expensive accommodation you can find anywhere in the city:  Hôtel Vicq d'Azir