Good stuff there, Rhino!
From my puny mind, here's what I have at the top of my head:
1 & 2. I think it requires both to truly understand the essence of the universe. There are things in the world that can only be perceived and understood by faith – unseen facts yet can be revealed by God however and whenever He wants to. There are also things that are clearly revealed for us to tangibly experience them. So, for me, both are necessary.
3. In line of what I answered in both #1 & #2,
“Whatever knowledge is attainable, must be attaiend by scientific method…”
This is the tangible part of knowing things. This can be done, and be pretty awesome if backed up with scientific method, but if it's not possible to have the tangible proof, it doesnt mean we cannot know it. We can know what love is (a construct and intangible) yet, we believe it exists.
“… and what science cannot discover, mankind cannot know.”
To me, still goes hand-in-hand with faith (evidence of things unseen). Science doesn't need to discover anything for us to know. We can still know if God wants us to. But since some of them are out there (the proofs), we can enjoy knowing more about God through what's already been and will be discovered.
Of course, again, to have the tangible evidence of things make it so much easier for mankind to make sense of things. But, it doesn't always work that way. Faith is necessary.. in fact, it's what pleases God. 
Just my opinion. Please correct me if I'm wrong. 