Actually i cant imagine how big is that cup .. Maybe take a pic of the cup on your hand? So we can agak agak the cup size

It's easy. If your cat is not overweight, then your cat is not overfeed. Cat like to eat a little at a time but frequently. Basically, they eat, they play, they poop, they eat, they sleep, they eat, they play, they eat..... 

Wet food is different story of course. Cats will clean out the plate in just one sitting. 
It's hot season anyway. Cats can be more sensitive than us human. They will drink more. Everyday I usually need to refill one drinking bowl twice a day but currently I need to refill two bowls twice a day (evening & early morning).

2 - 3 days? That's quick. Too quick. Worst case scenario should be a week. How many cats share the litter box? Maybe adding another litter box, you know, splitting the load.

same case with mine lol
i threw pillow at him...

i think your cat lonely after finish everything it wants to do at night and now demand you play or feed it

how many litterboxes do you have? how often do you clean them? do you use enzymatic cleaner on your sofa and beanbag?

Enzymatic cleaner is a specific kind of cleaner that breaks down the compounds in animal pee and poop so they don't pee/poop in the area again. Cleaning it with bleach or regular soap is not enough.

the general rule is number of cats + 1 litter boxes, so you should have three. Two at minimum, for two cats.

Have you taken the cat to the vet to rule out medical problems?

I use Smartsift for almost 4 years & my cats don't have problem using it.

Regarding the smell, are you referring the smell in general or the poop still smell even after buried? I did tried Oko Plus but it was two years ago.

Your cat should be able to learn how to enter with the door. When they really need to go, they'll try to push the door.

depends on ur budget..
u wana flush down toilet?
wana be more environmental frenly?

in summary, if u got $$$ silica is best. cat oso like.
save money but  not environ frenly, clay litter, can find cheapest.
flushasble litter like corn, soy type are $$$ more than silica.
pine pellet for me is messy n alot hard work, u can tanam the pine dust..

Had the same experience with the spray. Then I try the pipettes (Bayer Advantage), on all of my cats at the same time. Vacuum everyday for a few days. Done. Now no more fleas.

An alternative, type 'ubat kutu' on Shopee.

they prefer flavoured liquid, thts for sure.. soup.. milk..  can drink til perut buncit...

adult cats shouldnt be drinking milk.