Hmm. It seems to end in one thing - random dice roll tables.
Personally (and I think the people at my table agree with this) I find this boring. There is even a mechanic for "Random Encounters". Don't do Random encounters. Instead think
a) What did the characters do?
b) How do their antagonists REACT on this
c) let the antagonists (and their henchmen of course ^^) react
Also I would avoid any encounters which do not "progress the story". Which works big time against random encounters. About the wilderness - just describe the situation the characters are in, bring in some hindernisses and obstacles, let the characters plan on this - and then let them do a dice roll. Based on what they DID. If it is a good roll - things happen as the characters want. If it is a bad roll - a complication arrives. And the roll should be based on what the character does (if he does some tracking - a Nature roll, if he tries a ritual to teleport to the destination (and this makes sense of course ^^) - an Arcana roll - like that).
The big flaw in "navigation DC" is - so let's assume the characters roll bad on this one. They don't reach their destination. Nothing happens. Passivity. Passivitiy is never good. Much better if a bad roll means "you reach your destination, BUT - " and those BUT's can be really big (you reach the secret cavern, but your antagonist was faster, and now you are there in front of his WHOLE ARMY - how do you plan to get into the cave without him noticing? Something like that... though that was just quickly made up...).