Rooting A Nexus 5 and Concerns Regarding Over The Air Updates? I am planning on buying a Nexus 5 for Christmas, to which I intend to Root it, so that I can use Rooted Apps eg Titanium Backup which would otherwise be unavailable to me.

If I root the device, but do not flash a custom rom or kernel, and instead keep stock android KitKat 4.4. :-

What happens when an OTA update occurs from Google ie to 4.4.1?

Do I lose Root and Rooted Apps ?

(Correct me if i'm wrong, if I Root the Nexus 5 and flash a custom rom, then the OTA updates would come from the XDA Developer for the specific custom rom you are using, rather than from Google).
If you root the device on the stock ROM, it will still offer to do OTA updates, but they won't work. OTA updates only apply to a completely clean system image that hasn't been rooted.

To apply an upgrade to your rooted device, you have to download the ROM image from the official Google site and follow the instructions there to flash it.