I booked a reward ticket from BOS-TLV with some interesting routing and have a few questions:

1) My outbound routing is BOS-YYZ-TLV. The BOS-YYZ routing is on Air Canada "Jazz" (whatever that means). The YYZ-TLV flight is on regular Air Canada. When I get to Pearson, will I have to go through customs and immigration, recheck my bags, and go through security again? (my layover is 5 hours so I'm not overly concerned about it if I do)

2) My return segment is more tricky. It's TLV-BRU-IAD-BOS. TLV-BRU is on Brussels Air, and the rest of the segments are on United. I have a 7 hour layover in Brussels. Will I need to go through customs and immigrations in Brussels and recheck my bags? If I do, is there a place to store my bags for a couple hours so I can leave the airport and do something else?

I logged onto United's website to view my booking and it looks like all 3 segments are on one ticket. Will I only have one checkin at TLV and be issued all my boarding passes, or will I need to check in again with United at Brussels?

3) This reward ticket was booked with Continental miles. In the event something gets screwed up along the way, who is responsible for rebooking me and figuring out how to get me to my destination?

I'm not sure if this is the right forum for this post, but I wasn't sure where else to put it.