To know how early should I arrive for a Porter flight, check out the check-in policy of Porter airlines. For more details on this readout this blog and get in-depth knowledge of the check-in policy of Porter flight.
You should also go through the Check-in policy of Porter flight or contact Porter Airlines customer support to get more information on this. The policy will make you clear with the rules about how and when you can check-in at the airport.
Electronic boarding is not issued to passengers with the basic fare. You can get this if you are a VIPorter member with Priority or First status.
Yes, you will receive a separate boarding pass for your flight when you check-in and when your connecting flight is operated by this airline.
If your reservation is eligible for online changes, then you can change the flight online.