Betty's Restaurant is definitely off the beaten path - it's south of the Falls a bit and away from the river in the village of Chippawa. They have great fish and chips, very good standard fare, pretty good service. It is a large restaurant, so even if there are a lot of cars and it looks busy, and there is a wait to get seated you still won't take too long to have your meal. I don't recommend Betty's for breakfast though.
OTOH, a place that is wonderful for breakfast Falls Manor on Lundy's Lane - get there early to get a quick seat, or else you'll be waiting in line at the door - often the line extends outside on weekends. Great value and really good service there. Love the Belgian waffles - but their breakfast special is a very good deal. Falls Manor is very close to the outlet stores - they are just a little further west along Lundy's Lane.
The drive along the Niagara parkway is very lovely - you can stop at the Butterfly Conservatory - it's located at the Botanical Gardens which are also lovely once spring and summer are here - not too much going on there yet. The Niagara Parkway will take you past Queenston Heights, through Queenston and on to Niagara on the Lake. NOTL is a very pretty historic town - there is very good theatre there, the Shaw Festival, nice places to eat, gorgeous homes, nice B&B's, hotels, shopping along Queen Street.
I agree that the St Catharines Museum at Lock 3 is worth seeing.
In Toronto you could try to get Blue Jays tickets. There is a ton of stuff to see and do all within walking distance of Rogers Centre. Art Gallery of Ontario, Chinatown, shopping on Queen St., Harbourfront....