Like I said everyone is different so there is no one right answer.
Your questions are basically un answerable.
You will never get the right answer for you until you actually do it.
When I first started it was really hard for me to gain because I was really thin to start with.
Once my metabolism slowed down is when I started to see gains come and the weight staying on.
That took a good 6 to 8 months to happen.
Seems some young people these days expect things to happen right now and they don't want to work for anything.

If you don't have time to put into it then you really don't want to gain and its a fantasy you are having.
Gaining takes time sometimes months even years plus dedication and effort on your part.
If you are not willing to put forth the effort then don't expect results.
10 days time you might gain 5 lbs at the most but when you stop you will lose it rapidly.
Heavy cream did the delay thing to me when I stopped drinking it.
It will put weight on you and IMO its the best product to get you to gain quickly.
Just don't expect 10 to 15 lbs in 10 days.

I never said those people aren't for real.
You missed where I said everybody is different so there is no set in stone kind of answer I can give you.
You won't know until you try it but all I am saying is don't expect much of a weight gain in ten days.
Try for 30 or or 60 days then you should see a difference.
You admitted to being new to all this right?
You are asking because you don't know.
I first started in approx 2006 so its been 14 years of experience for me so I do know something about weight gain.

First off yep that is a newbie way of thinking.
10 days is not near enough days to see any results.
Just because you take in X number of calories does not mean you will gain Y number of pounds.
Too many factors involved like your metabolic rate and how long it takes your body to adjust to the increased calorie intake.
How long it takes your body to process that increase .
No two people are the same so if you try to get all scientific about it then you are wasting your time.
When I first decided to gain it took 3 months of overeating and many days feeling absolutely ill from over consuming to see my weight go up and actually have the weight stick and not lose it .
There is way more to gaining than you realize and its not all that easy.

Its like being thrust back into high school.
Very cliquey and if you don't fit in with the cool people you are talked about like a dog.
I was on there when it first started up and left in one month because of all the hate on there.
18 to 20 year old girls who thought they ran the place always bitching and moaning about something childish.

I live in the fat world every day and really don't delve into the fantasy part of it.
No fetishes or kinks just boldly normal is what I am.
Call me mean things and make fun of me I would probably cry LOL

I never understood the whole wanting to be teased and fat shamed.I get its a fetish and people are into it.
My point is when you are actually fat and people treat you like crap and talk to you like there is something wrong with you isn't pleasurable.
Fat shaming for real is an ugly thing.
People that have never been fat don't realize its not a nice thing to be teased about your weight.

My guess is he doesn't.

Heavy cream always cause me to gain rapidly and continue to gain after I stopped using it.
How it affects you may be totally different.

Kind of in that situation right now.
Lost close to 80 lbs last year because I had gotten so heavy it was getting hard to do normal things.
I have gained back 15 lbs of what I had lost and I feel kind of guilty and naughty about it.