Answer: If the flesh was dry on your satsuma, it was overripe. It's hard to predict when citrus might be fully ripe so periodic tasting is the best way to determine exactly when to harvest. As your satsuma matures and sets lots of fruits, start tasting late August. It usually begins ripening then, with fully ripe fruit in September or early October.
The insects you describe could be mealybugs or scale insects; both can be controlled with handpicking or with Insecticidal Soap.
As for your new dwarf orange, the curling leaves with browning on the back sides may simply be a symptom of sunscald. The important thing is that it gets adequate water and be allowed to become established in its new home. Don't remove the fruit; if the tree is able to develop them to maturity, you'll have a bonus. If it cannot, it will simply drop the fruit on its own.
Best wishes with your trees!
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