wrote:

For starters this part of Lk. Mich. gets arr & dep traffic from ORD.
How responsible is it
to attempt a take off without telling FAA controllers?

Perfectly responsible. Even very close to ORD, the controlled airspace only goes
down to 3,000'. In other words, there's over 2,300' of airspace above the lake
that's uncontrolled. It would actually be irresponsible to try to talk to ORD;
the controllers there are some of the busiest people in the world, and they have
no desire to talk with aircraft that are outside their area and intend to remain so.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.