Question about Samsung Galaxy A71

Good day. After 3 1/2 years I unfortunately have to say goodbye to the S7 :-(. Now my questions to you: Is the memory expandable via microSD? By how much? How "waterproof / splashproof" is this A71? Is it possible to take photos with this device in heavy rain? If I often carry the A71 in my pocket, is it a disadvantage if it comes into contact with sweat? Or are rain, sweat and splashing water a risk? What alternative would there be? Thank you very much for your answer and kind regards