I'm not sure if rooting with affect OTA updates. But I didn't think much & went ahead with rooting with TWRP recovery installed.
My set was shipped with CM 11-20140707-Nightly-bacon but the LED was not working. Then I installed CM 11-20140719-Nightly-bacon & things are working fine now.
I did received an OTA updates prompt for CM 11-20140709-Snapshot-M8, but my calendar & crashed. Even the Setting crashed, can't get in to check things.
rooting by itself normally doesn't break OTA i think, its the custom recoveries TWRP/CWM that do. But sometimes you need custom recovery to get root. At least this is so for other OEMs. so.... yeah. hahaha. But even if you get OTAs, those will likely break root.
But CM11 (not CM11s) is different as it comes pre-rooted. And if you use CM Updater, it doesn't care what recovery you use.
But anyway, unless you die die need some root apps, or want to tweak things, or what not, root doesn't do much for me. I normally only root if is low end or old phones so I can remove unused apps to free up resources and memory.
Here's a great article by Jerry from AC on rooting.
There is no magic in root | Android Central