SK, if you're only making very little porridge for baby (how much can a baby eat, right?), you're better off using the stove. as the name suggests, it's for slow cooking - for food that requires longer cooking hours eg. bird's nest, stew, soup. will try to answer your Qs:-
2) Do we have to cook the rice for like 10mins, then transfer into slow cooker to cook? or can directly cook in slow cooker? can cook directly but it will take longer as the cooker needs to heat up to boiling point. if you cook the rice first or add boiling water to the slow cooker, it will speed up the process
3) wadz the diff between using slow cooker compared to cooking on the stove? the main diff, in my opinion, is texture of the food
4) if i'm using a pot to cook porridge, i can monitor if too much water and can pour out excess. but slow cooker, coz of its function, wad if i put too much water? will my porridge become too watery? from my experience, no. just stir into the porridge. it will still be like cantonese-style