Thanks for the detailed response! That is a ton of great information for me to take in. I am so glad I asked.

I'm glad you found it helpful; that's why we are here! I learn something new every week here.

Are you near Seattle?

I'm in Victoria, BC.

Yes the cable does run through the seam piece.

That was not unusual with that type of extrusion. It means that, unless you remove the extrusion completely, you need to seal that center channel at the bow with sealant before you cover it up in any way. There will be a 'hole' into the cockpit from that channel where the cable comes out, probably. You don't want water from the bow finding its way back into the inside of the boat.
Patching the bow won't be difficult, but the joint between the vinyl extrusion and the repair will be critical. You might consider using an adhesive sealant (in black) like a Sikaflex product or 3M 5200 or similar, to 'fill in' around the bow and give a similar appearance to the vinyl. It will need some experimentation and will be messy. mask off the clean areas well. That vinyl extrusion was quite stiff, even when new, so problems getting it to bend around a tight curve were common, according to an expert I asked.

I was considering using this technique to repair the front.

https://www.youtube.com/watch?v=AgNypY6x_mk

Aah...typical NDK quality work! In a well-built boat, you need to grind off the seam tape, both inside and outside. Seam tape should not just 'peel off' after scoring the end with a knife! And, gelcoat is not the right 'filler' to put over the outside seam, under the tape. The outside seam tape (if applied properly) can add a lot of strength to the joint.

Here's a better example from Stealth (next up in the YouTube playlist):
https://www.youtube.com/watch?v=Hr8yntysgZQ

Notice:
-grinding
-resin and Cabosil (silica) filler
-two layers of glass tape
-more sanding
-black gelcoat to cover

Both those videos are about repairing a glassed seam. Your situation with the vinyl extrusion is different. It would be possible (though intimidating) to remove your vinyl extrusion and replace with glass seam tape, capturing a rudder cable tube under the tape at the aft end. It's not a lot tougher to replace a whole side seam, vs a foot or two - it just takes longer and uses more materials.

I will post pics when I get going, I will probably have questions about products...

Somebody will be here to help, unless everybody is off paddling!

Is your boat a PWS or an Eddyline boat? Is there a Hull Identification Number (HIN) scratched into the hull just below the seam on the aft starboard side ? Sometimes the HIN was written inside the boat; I've seen them up under the deck. Sometimes the old labels or ID plates disappear or fade over time.