Q.Strawberry Problem
I’ve planted a small strawberry patch (13 plants) this year and have noticed a few strangely shaped berries, plus a cracked (at tip) berry. I’ve enjoyed just 3-5 fully grown sweet berries so far, though each new plant is producing numerous berries. Also, some ripening berries have small holes in them. I presume that a bug of some kind is boring these small, shallow holes. Which bug could it be?

The strangely shaped berries you refer to are called "nubbins." There are a few reasons why these nubbins may be occurring. The weather is one. Cool, windy or wet weather will keep bees at bay when pollination should be taking place. Another reason for nubbins is frost damage to the pistillate part of the flower or lygus bug feeding activity.
As for the holes in your strawberries - snails or slugs are most likely the culprits but there are many other insects which can be equally as culpable. Birds too, even. Try inspecting your strawberry patch at different times of the day and see if you can spot the culprit.
For more information on growing strawberries, please visit the following link:
https://www.gardeningknowhow.com/edible/fruits/strawberry/growing-strawberry-plants.htm