Absolutely. There is no differentiation between present simple and progressive in Hebrew.

Unfortunately no. You should memorize it.

Nouns that end in ה get changed to a ת when they are combined with words like in these examples. You are adding descriptors. It's like adding the word "of" in English. It's not just a cake עוגה its a cake of chocolate. Same with ארוחה. By itself it means meal. But when you add descriptors (morning, afternoon, or evening) it becomes ארוחת, the meal of whatever time of day (breakfast, lunch, or dinner). It happens similarly with the word בית but the pronunciation changes, not the spelling. So house is בית bayit, but house of books בית ספר (ie school) becomes bet sefer (as an American i was taught it was beit like the English word bait but Israelis don't usually pronounce it that way). Or בית חולים bet cholim literally house of the sick means hospital