Thank you all for suggesting more tops! It makes sense and I completely agree, I was too concerned on the size of the cabin bag allowed (40*20*25cm). As for the open sandals, I am afraid it will be a pass for this trip: I had a minor hiking accident few months ago and damaged 2 toenails, so open sandals are a no-no until they have grown back. I can already hear my mum questioning me.... Best to use the white shoes which are suitable for warm weather.
I can do a quick laundry on the second half of the trip, however will need to cover the first half without much repetition. There won't be any time for sunbathing this time, which is great as I would panic about swimwear, I am already struggling to find a swimsuit for the pool, I doubt it would be easier to find a swimsuit for sunbathing (in less than a week!).
The foldable navy jacket is rainproof and I'll take a pair of sunglasses plus a cotton navy blazer which I don't think I have it in my find. The hat is a good suggestion too and have one but I don't know how to travel with it as would not be able to fold it so I was thinking of using the linen scarf as a headband if the weather is too hot.