A few thoughts
-First, WHOA.
OK then
-the T-line should be extended to meet the S-Line by going west through Ancaster along Golf Links and Wilson. (resurrecting part of the old Brantford & Hamilton radial)
-It's funny to talk about the S-Line along Garner-Rymal-Centennial, when a lot of the route is still undeveloped farmland. I know that by the time the S-Line is complete the area will be built up, just like along Upper James with the A-Line, but there isn't even bus service along a lot of this route.
-Extending the B-Line east along Queenston and then down Fruitland to the QEW is a great idea, but I remember that Stoney Creek was very anti-overhead wires back in the Trolley bus days. Hopefully things have changed. This would also mean that GO trains could be extended east from the James St station, and a GO station at Fruitland Rd would create another big transit node. (The S-line should also be extended down Centennial to the lake to connect with the GO.)
-I'm going to assume that the L-line will actually reach downtown Waterdown, they just couldn't fit it on the map. Because right now the L-line looks like it ends halfway up the hill toward Clappison's Corners. (Perhaps a new GO station should be built at Plains Rd.)
-Finally, with a network this big, we have to put in some connecting non-revenue tracks, so that we can divert trains in case of maintenance or accidents.