I'm very much in agreement on many of the issues you raised ... the one thing I'd add, on top of all that, there is a larger problem at hand in Toronto - and while many can't seem to admit it, it's taxes, and they are a big issue - just google it and you'll see many many papers / articles / ... regarding the issue. Does it effect downtown directly? No ... but the rest of the 416, of course - taxes are almost 100% higher in Toronto - think of someone at 404 and 401 vs 404 and 407 - why wouldn't you relocate to the 905 ...
Check this out:
http://www.toronto.ca/business_publications/pdf/2010-july.pdf
Taxes and Operating Costs: (Q1 2010, Q4 2009 ...)
Central Area $22.10 $21.75 $21.65 $21.58 $21.58
Suburbs $14.16 $14.09 $13.87 $13.88 $14.01
For all the talk of decreasing tax you can see we're actually increasing it in effect ... this is a per square foot charge ... it adds up fast. On top of this is the market driven net rental rates ... those are pretty close actually (market driven) and they're pretty close i.e. not a lot higher in Toronto as you may expect because the taxes are so high.
Anyway, back to your point - I do think we should set up several employment areas i.e. NYCC, downtown, VCC, MCC, Hi-way 7 / 404 ... so on ... that's okay ... but here's the problem, many of these nodes in the 905 turn out to be sprawling waste land of big campus developments. The wost is Mississauga around the airport, where many large companies have moved their call centers / IT centers / even headquarters from across Canada (that tells you how attractive the GTA is overall) and from Toronto (tax issue) ... if you drive in this area, it's terrible how spread out things are and there will never be a fix, they're built in such a way that prevents it from being fixed.
I have more hope for VCC and MCC in the future - VCC, basically has 0 (very little) non industrial employment right now, they're starting from scratch - the other area is Markham - where it's a least somewhat concentrated around hi-way 7 and eventually the new downtown Markham ...
And how about the outer 416? Basically looks like it's done for good, no more construction ... no more employment growth, and likely a very slow decrease in employment over time.