The first two have responses as of the time that you posted this. (If there are remaining questions in a post they are far less likely to be answered after the first couple of replies.)
The final example suffers somewhat from 'nobody knows what science doesn't know'. There are probably not too many people who can think of an example of a problem that UDT1 can not handle. For my part I probably wouldn't answer just because I don't like the name UDT1 and the language used to describe it irritates me.
I'm not sure why Eleizer didn't answer but I probably wouldn't bother wasting thoughts wondering. Want an answer? Make a top level post about it. Include enough of a useful description of the theory and the problems it has already solved to make you not look bad. In particular, include links to said problems and resolutions. If you really want an answer then include an assertion that UDT1 has solved all the significant decision Problems that have been discussed on LessWrong.
the language used to describe it irritates me
Please expand on that.
Want an answer? Make a top level post about it.
Why should I make that much effort to get a simple answer to a simple question? Eliezer obviously had something specific in mind when he wrote "Problem". Why didn't he just write a couple of sentences saying what it was when I indicated that I didn't get the reference?
Same with the other two questions. I wasn't asking difficult questions, just simple clarifications.
I declare this Open Thread open for discussion of Less Wrong topics that have not appeared in recent posts.