Since we rely on frozen meats, batch-storage of sauces, and don't plan well, I don't see any alternative for defrosting. A lasagne might require defrosting sausage and tomato sauce; a stir fry needs stock and chicken thighs; etc.
We do bacon in the micro -- it's faster, but I'm not sure it's better or easier to clean up from.
Reheating leftovers is pretty common. How else would you warm up last night's pad thai? I have found I'm using my Breville "Smart Oven" toaster oven more for reheating things, though, especially pizza. Wouldn't work for pad thai.
We don't do any micro-specific packaged foods (hot pockets? bleah!) popcorn is better with oil (Stir Crazy forever!); baked potatoes need crispy skins. We have on rare occasions made mug dishes such as molten cakes or "poached" an egg over leftover veg.
If ours died, I'd want another. They're cheap, but they take up space. Thankfully we have a big kitchen, with a cabinet shelf designated for the microwave.
What is patriotism, but the love of good things we ate in our childhood?
-- Lin Yutang