The first 3 examples of hello all functioned as I thought they should. But when I got to the fourth one, I expected a form with some prompts and a link. Rather, all I got was a web page saying It's alive. Where did that come from?
"It's alive." is just a tongue-in-cheek message printed by default to the root page (probably http://localhost:8080/) of a running instance of the Arc server. You can see where it comes from if you open the file srv.arc in your arc directory and look for the line:
(defop || req (pr "It's alive."))
The || from that is a symbol for empty, so just as your (defop hello ...) command puts a page at http://localhost:8080/hello, (defop || ...) puts a page at http://localhost:8080/. (Nothing comes after that final slash since we used the empty symbol instead of "hello".) You could replace the default "It's alive." message by running a command like
(defop || req (pr "jsgrahamus rox!"))
at the REPL.
Were you able to get this stuff working, by the way, or are you still stuck??