ahh....fix it..AND ask Santa for a new kite for Christmas as well!!!
Were you are you located? There might be a member nearby that can help guide you on this.....
The nose....yep, you are thinking correctly.....pull the rods out....then you can remove the one there (I would take photos of this process to help remind you how it goes back together again)....
Seat belt webbing would be fine to replace it.....fit it back onto the nose of the kite...sew the lines where they were before....and then trim the edge up....
The tubing: I am sure you could find replacement tubing at a hardware store....
OR
you could just upgrade all 4 of the fittings at once for a few bucks by getting the newfangled molded rubber ones you can find by clicking here:

Keep at it....they live very long lives with relatively few repairs needed to keep them going!!!!
r