Any difference between "terluas" and "paling luas"? And between "luas" and "besar"?
Terluas and paling luas are interchangeable. There is not much difference between luas and besar; although I have found that luas is usually used when you want to say 'spacious' (large) whereas 'besar' simply means big.
There is a subtle difference in their meanings. luas means vast, more like wide as in "wide open spaces", whereas besar means big. Like, if someone was talking about the size of a field, they would be more likely to use luas instead of besar, but they are mostly interchangable because of how general besar is in meaning. Luas is a bit more specific, and usually used more often with empty spaces.