How can i make our coop better?

Hi! I (18F) have had chickens all my life with my dad's help of course! We built this gorgeous hen hotel for when we had 5 chickens but unfortunately 2 died of old age and another of illness so we only have 2 now (we are planning to hatch/ adopt more in the spring) I already have a few ideas but i need some guidance 😁 We live in England so we do get a lot of rain leak through the roof we made.

1) paint the wood a nice colour (maybe a light blue or purple) 2)something to stop the coop from getting muddy!! (i was thinking wood pellet bedding but wont that rot? ) 3) more enrichment (any ideas on what?)

Any suggestions on how to improve my baby's home are welcomed !!