It would still be warmer near the equator (why should not be so?). The main difference in climate would be that there would be big deserts inside the continent and bigger differences of temperatures (It was so on Pangea and even today, simplyfying, the further from the ocean, the drier and the more extreme temperatures, like on Gobi desert. It is so called continental climate.). The Pangea megamonsoon was and would in your scenario be "a distinct seasonal reversal of winds, resulting in extreme transitions between dry and wet periods throughout the year", in analogy to modern monsoons.
Some animals would spread, at least from east to west as from north to south differences in climate make it harder (we know about Pangea, among others, because we find fossils of the same animals on different modern continents — see image), but not all (Eurasia is one landmass, but there are no Siberian tigers in Europe).
I do not see much reasons to expect substantial differences in natural disasters. Most earthquakes happen at the boundaries of continental plates, but this includes boundaries inside continents like East African Rift and Himalayas:
Tropical cyclones begin mostly above sea, so would of course more rarely go above land, if the coastline were shorter. Megamonsoon means droughts and floods.