I suspect that some of these price comparisons may be confused by the dire exchange rate for the Canadian dollar, which is probably the currency used for the quotes from Air Canada since you live in Canada. That aside, AC has been consistently cheaper out of Windsor to Europe than Delta/KLM/Air France from Detroit. For several years, back to when the dollars were at par, AC has beaten the Detroit fares by hundreds of dollars, at the expense of flying a puddle-jumper to Toronto and making an extra change of planes. Cheap parking at Windsor airport, too.
The schedules suggested by Ken certainly have safer time margins for the connections, especially on the return flight. Toronto Pearson is an efficient airport but it does sprawl so there is a lot of walking to reach the commuter to Windsor, with several security checks along the way. Border clearance is different for US citizens than Canadians, even though you live in Windsor, so you would need a lot of luck to make the connecting westbound flight in an hour. But the AC subsidiary running that route will have another flight in a couple of hours, as long as you don't choose the last flight of the night. I'm assuming your whole itinerary is with AC and its partners such as Lufthansa, so AC will take responsibility for the connection.
Here are recent developments to be aware of. It is becoming increasingly common to face an additional charge to reserve a seat in advance. That will be particularly true if you choose a flight operated by the AC subsidiary Rouge, intended to be "low cost" so you pay for extras such as in-flight entertainment. Security is much stricter than the last time you flew so learn what cannot be carried in hand luggage. Duty-free alcohol may be restricted from hand luggage if changing planes. And on the trans-ocean flights the carriers want you in your seat at least a half hour before takeoff.
