You have plenty of time for your connections, and you should have no problems with those times whatsoever.
The busiest time for customs at YYZ are very early in the morning, when there is a lot of US business traffic, and early in the afternoon, when the trans-Atlantic flights arrive. You're avoiding both of those peak periods, so you should be through Canada Customs in 10 to 15 minutes.
You'll pass through customs then go down an escalator to the baggage claim area. Pick up your bag, exit to the main arrivals lounge, then you go back up another escalator to the departures level and check in for your domestic connection to Moncton. The whole shebang should normally take a half-hour or less.
It's basically the same routine for the return trip, with the exception that your bag will be checked straight through to DFW. You will need to exit security, pre-clear US customs, then re-enter the security area again. Expect a half-hour for customs, and maybe 15 minutes for security if you do this before dinner ... perhaps allow 30 minutes for security if you leave it till after 6 pm (when pax for the outbound trans-Atlantic flights begin to arrive).
You'll be passing through Terminal 1 in both directions and there is food in both the US and Domestic wings. Visit
www.torontopearson.com for a terminal map and to see what there is for food, duty-free, etc.
Enjoy your trip! U2 puts on a great show.