I never think a concrete issue will affect me. But over the last weeks I've been affected exactly by 2). Today I finally figured out that it had to do with the sender having turned on the setting "Never send encrypted messages to unverified sessions from this session". It's terribly implemented, because it gives the sender no feedback that they break any unverified receivers, and the unverified receivers only see an obscure error message. For more details, see my issue report: https://github.com/vector-im/element-web/issues/18255
Also +1 on Element's terrible UI and UX. It was designed by programmers instead of UI designers, and you can feel that. I always find it weird when people talk about Element being a good client. It's literally the best of the worst. From the thousands of open issues (5000+ Web, 1000+ iOS and Android each!) you can clearly see they have an organization problem. Even most volunteer open source projects are more organized. I hope at least 30 million will be enough for them to hire some talented people and build a better management.
I have the feeling most of them are hackers. Hacking and experimenting with new things like Matrix P2P is great, but it's not enough to have consistent output. You need to manage an organization, and I have the feeling they aren't capable of doing that. On that note, I'm surprised they managed (pun!) to get 30 million of investment.