Excepting the Hackberry, all of the above are cultivars.
Autumn Blaze Maple is an Acer Freeman. So a cross between a Silver Maple and a Red Maple.
I'd prefer you went with a straight native, but that's me. Its your place.
Upside with this tree, bright red fall foliage, fairly hardy, will reach a good size, downside would be that its a clone (if this tree ever faces a pest they're all goners because they are all identical twins as it were.) also its fairly shallow rooted, so you're likely to get a bumpy lawn in the immediate area of the tree, over time.
Hackberry is densely foliated, and medium sized, also pretty hardy. Fall foliage is bright yellow to yellow-green.
The big upside, its excellent for local wildlife: (as per LEAF)
It is host to at least five different species of butterfly, including the Tawny Emperor, the Snout Butterfly, the Morning Cloak, the Question Mark, and of course, the rare Hackberry Emperor. Its fruits are attractive to many birds (especially in the winter), including cedar waxwings, woodpeckers, mockingbirds, and robins. The leaves also provide food for many caterpillars.
Downside might be that its not a giant at maturity (But that could be good to, depending on your needs) They also produce some fruit you may need to clean up if the wildlife don't get them.
The Linden is a hard no for me, first because its a cross with a European species, Little Leaf Linden, which is often invasive in Toronto's forests; but secondarily because I find the shape unnatural and goofy looking. Its very pyramid'ish.
Not particularly big on Homestead Elm either, if its the cross I'm familiar with, its 1/2 Siberian Elm. (fairly resistant to Dutch Elm disease though).
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Of the above, from my perspective (not yours), I would go w/Hackberry. Maximum ecological value, full-native, not a clone.
I haven't seen your site, but based on your description, mostly sunny, decent drainage, and the list of species you were suggested....
Do you mind nuts?
Red Oak would be lovely, pretty reliable, fond of sandy'ish soils, but will do fine in rich soils.
Bur Oak will put up with almost anything.
Both are easy to find from Toronto area nurseries.
If you went with either of those or any other nut-bearing species, best to have it planted in the spring. Nut bearers and conifers get more stressed when you plant them in the fall.
If you wanted something Linden'ish; the native is Basswood (Tilia americana); can be a bit of a slow grower, but will be a giant one day. (if you go this route, insist on the proper thing, there are so many cultivars)
I could offer more suggestions but would want to know your soil a bit better (sandy, vs rich loam (black/fertile) or more clay'ish.