DAVIDN

The Chime app is a standalone app (C4 Intercom) and runs on IOS, so yes- you should be able to have it ring and display video on any device running the app, including an iPad.  
HOWEVER- If you don't have any C4 screens or C4 audio, I would suggest a Ring doorbell instead.  I went from a Ring Elite to the Chime and I'm seriously considering going back.  The Chime is nowhere near as intuitive as the Ring, nor is it as flexible.  The Ring app makes it simple to configure all aspects of the device- snooze motion alerts, change sensitivity, set motion zones, view past events with video, etc.  The Chime is just far less sophisticated.  Or at least less sophisticated to the common person with C-HE available. 
Motion alerts are inconsistent and have to be configured in C4.  My installer still has to configure something because I have zero access to past video or motion events.  That's right- a video doorbell that I can't see any history.  Who knows why.  
Oh, and the video quality of the Chime sucks in comparison to Ring.  

I also am using Ubiquiti with no issues.  I'm not an IT pro, but setting up the EdgerrouterX and AP's wasn't hard in Unifi.  There are plenty of YT videos that will step you through it.  Be aware that the Neeo remote has APPALLING wifi performance, so make sure your wifi is overbuilt.  My iPhone reports RSSI at least 10dB hotter than the Neeo.  I had to add an extra AP in my 5k sqft house (two LR and two Pro) just to keep the damned remote from dropping.  
Also, I'll second the "Luma is crap" comment- at least compared to Ring.   The video quality is pretty terrible for a 4k camera- note that you can barely read the Prime logo and you can't read the yard sign.  I'm sitting in my office right now and I can read it just fine from here. Forget using this for any sort of forensic work...
Luma motion sensor zones don't work.  See snapshot...  The feature is there, but it doesn't work.
The ONLY reason to go with Luma is so you can use your TV or T4 Touchpads to view the video.  Otherwise, I miss my Ring stuff....

I did the same thing in the master bed/bath.  Additionally, in the Amazon app, you can set the local dot in the room to ALWAYS play audio out of the dot in the A/V rack so you don't have to add the "on the Party Dot" line to your command.  Create a room in Alexa called "Kitchen" and add both Dots.  Under Speakers, select the Dot in the A/V rack as the only speaker and all audio will go through the dot in the A/V rack...
I have my EA5 to leave the MDX16 on the A/V rack dot input fulltime except when I use the C4 keypad/TS/remote to play audio in the room.  When the EA5 commanded audio is turned off, it reverts the MDX to the dot input.