Hi @lynx these are good questions and folk here will be happy to help you understand how the network promises to handle these issues. To start though, it would probably save some time if you first take a look at the https://primer.safenetwork.org/ which is a technical description of the network written by members of the community to help this situating. I think it will answer some questions and give you a much better picture of how things fit together, and how it can fulfil its very ambitious goals.
If it doesn’t help please let us know too, and we’ll try another approach, as well as answering any follow up questions you have.
The Primer is a little out of date, but still a good technical introduction. The main thing that isn’t in there is I think PARSEC, a new consensus algorithm, but there are videos, slides and other descriptions of that if you want to look into it. Searching the forum should help there.
I also recommend reading this post which one of our members updates from time to time, which gives a good introduction to the capabilities from different perspectives.