Good for you!
My thoughts:
The mast section is strong enough for a Hobie 14 so even if it's not as strong as it used to be I defy you to try and break it. It's gonna be way too strong for you even if you have an adventure with a trailer and a low bridge.
I usually drill with 3/16", which is probably too big but it's what I have in my toolbox. 1/8" would probably be better. There's a foam plug in the mast about 10" up from the bottom of the mast extrusion. That's sealed in there to keep water out. Or to keep water in, in your case
. You want to drill above that to get it to drain. I drill inside the lips of the sail track. I don't seal the hole. My reasoning is that when the boat is capsized the top half of the extrusion is out of the water because the mast is supported by the Bob.
I read about some guy who managed to invert his Wave but mine floats on it's side so the drilled hole doesn't get close to the water.
There's the same plug at the top of the extrusion to seal out water. The problem is that rain water runs down the comptip and sits on that plug. If it's not perfectly sealed, like yours, because the sealant around the edges dried out, then the water runs down inside. So you should reseal the edges of your mast plug.
Your mileage may vary.
Charles