Many of the changes you suggest would make JWs a better religion in my view. But they certainly wouldn't help them to grow. Strict religions grow faster, not ones that soften their requirements.
And it's true that many older JWs are realising Armageddon will not come before they die. But this is a realisation that aging JWs have always had to cope with as death approaches, whether that be in the 1950s or the 2010s. What's different now is that the GB is not offering any consistent reasons for thinking that the end will come soon. But this is not a necessary development for JWs. They could come up with new reasons and carry on as before. If they did, that would be their best chance at growing in the future.