> 1. That consciousness itself is simple enough or even possible to obtain by digital means
While it's true it hasn't been and maybe will never be proven that it is achievable trough digital means, that doesn't mean that it can't be achieved trough analogue means. Veritasium made a good video on the topic of analogue computing and I recommend giving it a watch.
And since nothing is stopping us from using a combination of digital and analogue technology to create AI, there isn't anything to disprove the possibility of sentient AI either. I can't say for how easy that will be or how long it will take to get us there, but if it's physically possible for brains to exist, then they can theoretically be replicated.
Unless souls turn out to be a thing and necessary for sentience. In which case, we'd need to learn how to harvest and slap them onto computers for AI to work. Would work out great for Ross, since he has some stockpiled.