Advice moving from Mythtv to TvHeadend

So I currently have a Mythtv backend running on Ubuntu (Mythbuntu) and a Librelec frontend running on a Raspberry Pi 2.

I’m starting to get fed up with the noisy backend and looking for options, I’m a very big fan of the Raspberry Pi and quite interested in giving Tvheadend a try but thought I’d come here for advice.

My initial thoughts are to install Tvheadend via Librelec on my existing Raspberry Pi, I have a HDHomeRun so not expecting too many issues getting channels to work and record. I also have a NAS that I would use for storing the recordings. I think my concern is that it sounds far too simple.

Does Tvheadend add much overhead on performance or would I almost certainly need to run 2 Pi’s? (To split the frontend and backend) – I do have the additional audio/video license on the Raspberry Pi so hoping that will help.

Can anyone see any issues recording to a NAS? My biggest headache is that by retiring mythtv I’m losing 2 HDD which is a large chunk of my storage, I could always add a USB enclosure and connect to the Pi.

I’m also interested to know how you access the recordings via Kodi, with the Mythtv add-on there is a recording menu, this is separate to the Movies/TV Shows menu in Kodi. Is there a way to make the Tvheadend recordings appear within the Movies/TV Shows menu?

Any help or advice is much appreciated.

Thanks