I don't have time to respond to everything, so I'll just respond to the first one- which is that it's tankie copium. I don't deny the Signal Foundation might be taking money from government groups- I believe it is. But looking at the groups its pretty clear what it is, Radio Free Asia, as in the Asia branch of Radio Free Europe. Aka, their goal is to make people living in US adversaries rebel. The US does not censor private communication, it would be very quickly found out if I sent a text to my friend and they couldn't receive it, or I was sent to jail for the content of that speech.(That's not to say its not spied on though.) However, in many(most?) US adversaries there is active censorship of opposition communication, the US generally(although not always) supports the opposition by nature of them being the opposition- this is why(if you believe the narrative that everything is a cabal of the powerful) US tech companies supported the Arab Spring. This is why Radio Free Europe broadcast in support of Dubček and the Prague Spring, why they also supported the 1956 Hungarian Revolution. All that is just to say the US can follow the narrative of being 100% power seeking while still supporting open communication platforms. (After all, the US government also either directly created or contributed to SHA-2, Tor, and Ghidra too) And, Signal is open source, read the code and network traffic yourself, they won't remove encryption for US allies.

That doesn't mean they're immune to criticism, they may be able to explain it, but I personally probably wouldn't donate to an organization that has the money to pay part time developers $450,000 according to their Form 990, but its not my money so not my place to judge how its spent.