Ola Simon
This is a diorama base with a lot of potential. With this I mean it can be virtually everything... Every village/city in Europe does have a church. From Spain to Poland you will find churches... Ok they do vary somewhat per country but that doesn`t matter much. This means you can add doesn`t matter what figures and it doesn`t matter what scene you create it is almost always good.
Couple of things I would change.
As other people have said put the church at a little angle. it creates more interest in the scene. If I had to decide I would skip the wall next to the church. it is really big. You probably had some work with it I can see that but it kinda distracts from the church.
Another thing worth noticing for further stages is the fact that a church usually stands at a square. In the early days the Church was usually in the center of a village and/or a town. The Market was also always held around the church. This means that you could have quite some area with cobblestones in front of the church.
In the cities eventually the square became less and less as more people came to inhabit the city and more houses needed to be built. In a lot of european cities you now have often a church between houses.
If you want to have a church ruin in a busy city you could have a house in the place where you now have your wall. Fun thing would be if the house is still intact. It often happened that one building was almost demolished to the ground while the other next to it did not even have shattered glass. Another idea could maybe be adding a little path on the right side of the church and next to that a graveyard which was not uncommon in those days either.
Now one thing returms everytime somebody builds a ruin.... Rubble. Make sure you have enough of it. I can`t really say how big this ruin section is but even a little church is a big building and will definately bring up a huge load of rubble. from complete pieces of wall to the smaller type of building stone often used in churches. Also a lot of wood.
As to the interior..... I`m not a believer but I love to visit churches... That is more for the building and architecture then the religion. Often you have at the entrance a little cabinet with bibles or prayer books or maybe it even are books with psalms I really don`t know but that might be a nice touch.
As for the rest.... I might think some other things up with your next update... I will try to follow this thread as good as I can as I`m really curious what you will make of it. It is in a very early stadium I know but looking forward to the rest
