Assembly might not be the primary language in large applications, but it is still valuable knowledge to have. You can also learn it without the need to understand every cpu architecture in the world.
Dual and triple is not about point to point.
To get dual you need two channels. Now you can have more than one module per channel. That is going to change.
Assembly is tough to learn, but it is good knowledge to have when you are programming a high level language. You can also do funny things with a debugger - when you understand the jibberish.
I am not sure what you mean by "virtual" then. Your article also says "physical", which is what pae is. 32bit applications can be executed on 64bit Windows without supporing a 64bit OS. Right? The same is true aboue PAE.
Only virtual? Not really. The reason PAE doesn't make all memory availble in desktop versions of 32bit Windows is because Microsoft made it so. Otherwise PAE can surely do the job.