Fresh Install of OS but what about the apps? I currently have OS X El Capitan installed on my iMac

I have backed up the whole HD to my 3TB NAS using "Timemachine".
I have formatted a USB flash with the El CApitan installer on it ready to install a fresh copy of the OS.

The questions I have are: 

Can I pull the applications as .app files and just drop them back into the /applications folder

Will this the way also allow me to get Microsoft Office 2011 back on after Ive reinstalled the OS or will i need my licence (when i find it?)
Yes, dragging an .app file to the Applications folder of a different Mac will work. It may be easier for you to just sign in with your Apple ID on the Mac App Store and download the apps you have purchased from there (if you find it easier).

You will be able to move Microsoft Office 2011 apps to the Applications folder but upon opening them you will be presented with a registration page where you will have to input your serial number.

As detailed in Microsoft's Office page, you will obtain your serial number either from the orange sticker on your installation DVD, or from the email you got if you purchased it online.