No. When done responsibly, those hairs were typically found to be from a Bison. When I was going to Uof Alberta we had at least 3 instances of hair being possibly bigfoot and they all came back as a woodland Bison.
Sounds are the result of people not knowing what they are hearing and jumping to conclusions. Completely unconfirmable as no matter what sound you show them they could say "Yeah that's not what I heard" to perpetuate their story.
Foot prints...really? One of the most widely faked evidences of BigFOOT.
Mysterious sightings are just that, mysterious sightings. They hardly confirm bigfoots existence; if you see something you can't quite make out or confirm, that's all it is. Something you can't quite make out or confirm.
The hairs you are talking about are totally falsified. How would could a hair be a cross between a gorilla and a human? Of course mammalian hair resembled apes. Most mammalian hair is pretty much the same, just a strand of keratin. It was likely a bison too, but the people didn't do the science right and now it's unconfirmable.
The Platypus and the Okapi were both thought to not exist. There was a large bovid discovered in S.E. Asia within the last decade. The past discovery has no bearing on present ones. I can tell you that area is widely traversed now by people. The more time and people that get out there, the less likely that bigfoot can go undiscovered. It's not like you're talking about the jungles of Congo, you're talking about 300 km away from a major city.
When animals "seemingly disappear" from the fossil record it is assumed, quite reasonably, that they are extinct. The Coelacanth was presumed dead about 250 MYA until a man who knew what they were (easily identified by the Caudal 'flag' along the midline of the tail) happened by one in a market and checked it out. It's not like someone set out to prove that the Coelacanth was still alive. No offense, but by the sounds of it you are not a trained man of science and you either believe or want to believe in this stuff.