Welcome to FT, mlv416!

1. I can't help since I don't know what this is, but you may be able to secure bulkhead seats with a baby bassinet if these are still available.

Edit: I googled this thing and it should fit around a PE seat on BA as long as you do not require moveable armrests (or indeed armrests that are shaped like arms and not walls.

2. No one can say with certainty whether there will be a sale or not. It's your gamble.

3. The armrests do not move up. They are fixed units.

I don't know how the TD system works, but if it redeems award seats you should first check that these are indeed available. If they are, then be advised BA has very high surcharges. For these reasons, you may wish to consider the daytime flight from YYZ to LHR with a toddler. Of course it may be that the TD points just provide credit against purchased seats.

Edit: How old is your child, and will it have its own seat? If so, then clearly the bassinet advice is nonsense, though you still may wish to consider a day flight if the child won't sleep.