As for debugging, I try to keep those commands in the quick reference guide under the debug section.
Though they don't include the js functions in startwindow that might help, maybe they should, maybe not, IDK,
at a philosophical level it's just the edbrowse commands.
So here is your list with some edits, the first few coming from the quick reference guide.
These work from edbrowse or within jdb.

db3 : set debug level, 0 through 9
db>/tmp/edbrowse.out : redirect debugging output to a file
jdb : javascript debugger, bye to exit
demin : deminimize javascript (toggle)
timers : disable javascript timers (toggle)
dbcn : enable cloneNode debugging (toggle)
dbev : enable event debugging (toggle)
dber : enable js error debugging (toggle)
dbcss : enable css debugging (toggle)

^> - the file redirect to your filesystem
showscripts - list all scripts
searchscripts - searches all scripts for a string
aloop

> error in f575d3.ontimer()

You have my head in a whirl with this one.
It comes from jseng-duk.c line 1790, from html.c line 2346.
So it's hex for the c pointer of the timer object that was created to run the timer,
but that object goes away once the timer has fired.
We would either have to make these timers not go away, whence they would accumulate, or perhaps print more helpful information before the timer runs.
The body attribute would be helpful, the source code for the timer,
but sometimes, perhaps most of the time, it isn't given source but rather a function.
setTimeout(f, 30000);
Hardly anything useful we can do with that.
I'll give this a little more thought.

Karl Dahlke