why not?
you could flash manually as well is you cant wait OTA to send over

perform a clean re-installation (refer to page 1 for guidance)
follow the instruction to setup your phone
install whatever you like

if yours is international set with cm11s preloaded, then you dont need to do anything, just use normally. if yours is china set flashed to cm11s then u might need to read abit about rom and flashing all those. seriously if you dont know anything about android and you bought a china set you will need sometime to get use to all the adjusting and tinkering with the phone.. ppl here mostly will suggest you too do those thing on first page because usually those who bought oneplus (esp china set) is familiar with android to certain level already.

serial number and IMEI are always two diff things

Btw did u installed any custome recovery?

Do you know the custom recovery ?

you need to follow the guide on first page exactly, to install twrp recovery before start flashing.

To be honest, if this is your first Android phone, just use it as what it is. After 6months of using when you are boring, come back here and we teach you how to flash rom and kernel.

In before that, setup a passlock for your android phone, install apps from PlayStore like WhatsApp, Telegram, Facebook, MX Player, etc... for more refer here on what are the basic essential apps you might need.
http://lifehacker.com/lifehacker-pack-for-...ntial-819094535

If you are not confidence enough, come back here often and see what other people feedback before pull the trigger update the OTA.

Guess what? I still on 38R which older than 44S. Lawl.

Read here for more:
http://www.xda-developers.com/android-basi...a-developer-tv/

To be exact, like you said, Kernel is a bridge that connect between the ROM (aka Software) and the Hardware.

For example:
If the Hardware (Phone) have Camera, but the Software (ROM) doesn't know where/what to do(lack of Camera APP) and (Kernel) doesn't how to do (lack of the API).

Same concept here if Human want to learn Badminton:
If you Human (Phone) have two hands, but you (ROM) doesn't know where/what to do (lack of Rackets) and your brain doesn't know how to do (lack of Badminton Skill)

Lol. How was my explanation?

if the stock kernel does the job for your phone, you dont need to change to another kernel.

the other alternative kernels offer more tweaks and controls to the users who knows how to use it.