After a long discussion with myself, my answers to the questions are:
1. Yes
They will be cacheable, shrinkable and easier to maintain.
"dependencies": {
"drab": "file:deps/drab",
"drab_query": "file:deps/drab" // TBD
2. Yes
Very short max_age. Drab client will grab it, and delete it from document.cookies immediately.
3. Yes
Standard Drab installation will just add plug to generate a token cookie, and Drab will start on load. We just need to solve the case, when you want to add something, like authentication token, to the connect callback. Proposition:
plug(Drab.Client, connect: false)
and
if (window.Drab) Drab.connect({auth_token: window.my_token});
Drab will not try to start if the commander is not present.
4. No
%Phoenix.Socket{} is enough. I will just do some housekeeping, moving all drab’s underscore assign to the one struct, and keep all under __drab assign.
5. No
We can’t. Session cookie is http only.
6. Yes
But I still have no idea how 
