hey, little export advice :
on your sketch style (the last one), you could turn on the profiles so the curves of the roof would show, if needed off course.
I think I recall Dave showing that exporting on higher sizes would give more detailed sketchlines. Like, exporting a 4000x3000px image will give your more and finer lines than a 1000x750.
If you need a smaller size, you can then lower your big image resolution.
edit : I knew I saved the thread for future referencing.
The Effect of Image Export Size
see how exporting bigger images gives thinner lines.
Sketch styles can be fine, but in cases with lots of small details, they can be a bit crowded to read if the lines are too thick 
stuff like complex furnitures or windows can appear really dark and messy with thick lines
but that’s not the point. it looks good ! I wonder how you made the claws/wings things on the main gate (horns ? flames ? they probably have a name, but I mostly learned about gothic cathedrals and baroque in arch school)