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.

Yup. I've tried both in my smartsift.
Both failed to do the job.
Cause the basis of smartsift is the clumping mechanism of the sand.

I placed floormat in front of the smartsift, 3 of them side by side to cater the footprint. 

Oh, does your cat has any problem using the smartsift with the door closed?
All my 3 cats refuse to use it when the door is closed. 

My cat sleep like this. Any cat sleep like this?

got my evo from waggy meal today, it smell a little bit like taste of the wild

btw, how to feed those wet food ? bought 2 fancy feast canned food, open and feed directly?

For those of us talking about amount of food, I think the best way to standardize it would be measure it in weight. For example, I feed my cats 1oz of wet food twice a day each, with about 40g of dry food left out for free feeding. I use a kitchen scale.

Showing us cups means nothing, since cups can be all sorts of different sizes and so can our hands.

incase u didnt realize the cup i used had measurements on it. i feed about 30g per meal for a cat. so about 60g of dry food a day per cat and my cat is about 3kg now. younger one is about 2kg
i dont free feed any form of wet or dry food in between.

i'm cutting down their meals to just 50g a day. i'll see how it goes.

Neutered/spayed cat can get fat & overweight but it doesn't mean they necessarily will get fat & overweight. Like spunkberry said, it's all about lifestyle & how much you feed your cat. BTW, I feed my cat twice a day & I make sure I didn't over feed them. I also don't like give them treats between meals.

I just want to say, regardless what brand or what kind of food you feed your cat, fat & overweight cat is bad, as much as malnutrition is bad to cat.
I don't agree with the bold part. Malnutrition cat won't look fit. They would look sick. 

My cat sleep like this. Any cat sleep like this?

My cat is ok with door close.
If i remember i open the door, then she was inside, then i close it. it took her few min to figure out how to come out. Then after that she knows how to use liao.

My cat sleep like this. Any cat sleep like this?

collar so lose, they're going to take it off on their own.

never happened, not even once.