Using the pass for the first time

I bought a mobile Eurail Pass "7 days in 1 month 2nd class" for the first time. I’ll be in Europe from May 6th to May 22nd and I’ll take trains in 7 days within that period:
a. With mandatory reservation, for example Eurostar (I already bought the tickets paying a discount).
b. No mandatory reservation (I still bought the tickets to reserve a seat).
c. Without the possibility of reserving a seat (I’ll show up at the station and take the train by showing the pass).
My questions:
1) I arrive in Madrid on May 6th, and I'll take the first train in London on May 13th. Can I activate the pass in Madrid?
2) Every time I take a train, do I have to show the pass on my cell phone (plus the corresponding ticket in cases a and b)?
3) I bought some tickets through Eurail.com and they appear in the application's "Reservations Overview". I bought other tickets through RailEurope or from the railway companies' websites (always indicating the pass number) so those are not listed in Eurail  app. Do I have to upload all the tickets to the Eurail app, or to take a train I just show the pass in the app and the printed ticket?
4) When taking a train on a new day, will the application automatically show the days consumed, of the 7 days that the pass includes?
Thank you!