We have raked ceilings in our new split level extension that follows the fall of the land (and in the rooms that were part of the skillion sections of the old cottage) and I love the sense of space they give and also the fact that the inside reflects what is happening on the outside of the house. We have used ceiling boards (painted white – I didn't want to feel like I was living in a cigar box) both in the old cottage and in the new section and they certainly add an enormous amount of visual interest to the rooms as well. However, I endorse the comments about the added trickiness of light fittings. Pendants with rods are out and pay particular attention to the little rose/canopy thingies that connect pendants to the ceiling – make sure that they sit flush with the ceiling and don't have weird unsightly bits that you can suddenly see because of the angled ceiling. We have successfully used LED downlights with a recessed diffuser and dimmer switches to make sure there is no glare but if the raked angle isn't too extreme they are a definite possibility.

To assist with harnessing the sea breeze suggest a beautiful long narrow feature window that follows either side of the pitch of the roof (which will let in a lovely sky view plus breeze), or just have the top triangle as a window. Understand the desire to have the small window there however in a room with big glass/window features, the small window looks like an after thought and is at the wrong scale.

The lounge in our 1956 house in South Africa had a stained wooden ceiling. The house didn't have any insulation so the lounge would become really hot in Summer. We opted to have the original ceiling removed and dropped 150mm so we could install insulation. We needed to paint the original panels but left the varnished beams. Every wall in the house was painted white, which I found too stark. I decided to paint the lounge using a light blue and a peach colour. People thought this was a bit bold, but I was happy with my choice. The before photos were scans from the 1980s, as I couldn't find the original EA photos when we bought the house.

For the best ceiling fan designs try Urban Lighting, they have a couple of shops in Sydney and some very unique designs in both traditional and contemporary. I have a deco house too and am looking at their lighting products for our new extension. The lines in your ceiling rose are sharp and square so I think a modern fan would look great, but luckily with deco you can go either way. The link is https://urbanlighting.com.au/collections/fans and below are some from their modern range which may compliment but not compete with the detail in your ceiling rose: