[ unmv2si001 ] Adding 8gb ram to the existing 4gb

Hi 

I just purchased a new e5-572g laptop.

The ram details form the linux os are:

Kingston ACR16D3LS1KNG/4G 
description: SODIMM DDR3 Synchronous 1600 MHz (0.6 ns)
size: 4GiB
width: 64 bits
clock: 1600MHz (0.6ns)
PC3-12800, 1.5V, 1.35V , CL 11, CAS Supported: 5 6 7 8 9 10 11 
Non ECC
Unbuffered

1. will this RAM go well with the existing unit?

http://www.amazon.in/Kingston-1600MHz-Voltage-SODIMM-KCP3L16SD8/dp/B01C22DZ3M

2. Is it even a good idea to pair a 8gb ram with a 4 gb one?

3. Will the Acer support tehmselves come to my house and upgrade the ram for me? The laptop doesnt have a backpanel and I have on site warranty.