no, it is true that dao exists, the proof is infront of your face right now. it is an empty framework which allows physical energy/matter to exist. take 1 cubic meter of space infront of you, what is that space?. true it holds millions of particles and various other forms of micro sized matter/energy. but what are those particles and energy floating around in?. it is a dimension of empty space that we cannot detect or sense. if you for instance, take away all of the particles and energy out of the cubic meter infront of you, what are you left with? empty space.
this empty space/force/frame is dao. it is not faith based, it is based on logic.
peace.
Well that understanding of Taoism may just be a philosophy. I think that among writers on Eastern philosophy it is common to distinguish that understanding from Taoism as a religion.
Actually it may be better to think of it as a spectrum of ideas, with a purely philosophical conception of the Tao at one end and the full blown conception of spirits and beings that make up Taoism as a religion at the other.
There is a lot to Taoist writings (including a political philosphy, a perspective on medicine/health, etc.) and I've always been impressed by the ability of some of those writings to encompass so much with so few words (so I guess you can a retoric to the list as well).