In my opinion it all depends how many holes you have in your boat, if the cockpit will drain rain water and how long your will be leaving your boat without checking on it.
My 25 has one below water through hull which has a new valve and is left closed unless needed. There are two other above waterline though hulls that are sink and cockpit drains. It would take a lot of water or other weight to put them under to the point they would allow water in.
There are no leaves or other debris floating around to clog the cockpit drain so rain won't sink it. If the drain did clog it would take many inches of water before it flooded the cabin.
So I consider my risk of sinking very low, too low to worry about installing a bilge pump and safe shore power setup when I have other upgrades to plan, pay for and install.
My bilge is normally dry but I check it each time I open the boat and if I find water I investigate where it might have come from. If salty it came from the bottom. If fresh it came from the sky.
Your boat, your choice! as Stu would say.