#2 is actually hard coded in to the board, and you flip a dip switch to get the "Delete" key to act as backspace.
As for #1, it isn't, as far as I know. I haven't had much luck getting OS X to remap any keys effectively, other than the modifiers, which is a function built in to the system.
Though, as the owner of an HHKB, I can tell you that you quickly adjust to the embedded cursor keys.
What IDE do you use, and can you use either vi or emacs cursor control sequences?
Edit: As I reread what you wrote, I see it isn't what I thought it was. The HHKB has FN + ` mapped to delete. Which really, is really really easy to hit one handed, honestly.