You have a lot going on texture-wise so I'd probably keep it simple in terms of rug texture or there'll be too much going on at once. Warm would do well in this room though, so that's good! You mention it's away from the light outdoor area, is this photo an accurate representation of the lighting you normally get in this room? So in summary, you might want to have a look at rugs that don't have much texture, and are a bit brighter in colour to help brighten up the room. Below are just a couple of examples of rugs that could work, and one more neutral example.

Two issues -- The middle size looks 'about right' and approx 40cm diameter ( approx 2/3rds the size of the larger one ) . But I don't think it suits many modern styles -- a beach inspired place with say white woven wallpaper or seagrass style flooring or some distressed furniture would be complemented by this , but a modern build with say painted walls doesn't do anything with this style IMO . Go classier rather than laid-back would be my advice , and that would depend on the decor . And thinking about things , one 'trick' I used in a commercial building I own was 5 polished copper shades up an L shaped stairway -- the ceiling was flat , so nearly 5 metres 'up' at the base , and I used 28cm ones with the biggest round clear LED bulbs ( 8Watt ) I could get , all hung on that oldstyle '1940's iron' type cord , so they were all 2.6metres above the stair below -- it created that 'going up' visual effect . One large light ( especially say 4 metres above the deck ) won't give that effect .

You could keep a picture there and add a second large portrait shape piece to left, or have a large wide piece to left, replacing current pic with a tall lamp or other item on dresser in corner to balance. Or just a slightly large where is leaving rest of wall clear noting it looks a narrow walkway

Working with what you have I would try moving the two seater to the left with one of the side tables to the left of that with the tall vase of flowers (or change out for a standard lamp). A side table on the right of the lounge without a tall vase then the lovely beige arm chair in front of the windows. Moving what appears to be dining chairs across the room At the moment everything is over crowded and pushed to the walls