Welcome! Please see the About page for a little more info on how this works.
Question: When I get an error inside a #object[] the REPL crashes and no command seems to escape, so I have to restart the terminal.
Ctrl + C and Ctrl + D do not work.
What kind of REPL are you running?
Note - this question originally contained multiple questions. I've broken those up into separate questions and focused this one on just the original question. Putting multiple questions into a single question fights against many of the goals and benefits of this site.
I don't have an answer but just posted what turns out to be basically the same problem. Let me know if you find out anything and I'll do likewise.