First of all, let me say that you have a great spot there. Mountains and a nice body of water! The best of both worlds.
I see the gimbal twitching that you refer to. What was your mission speed? It looked fairly fast. For a flight like that, I would set the speed at 10 - 12 MPH, and you can always speed it up in post editing if necessary. The twitching does not appear to be a problem per se, but is simply Litchi's algorithms making camera pitch adjustments based on the point of interest (house) and how far the copter is from it. You may eliminate some or most of this twitching by selecting 'Interpolate' under the POI settings for each of the waypoints you created. Copter speed is the big thing though, and you may want to slow it down a bit.
Here is the link to my above mission on the Litchi Hub. It was a very fun project between planning, executing - several times and several tweaks to get it right - and finally, editing. There are other videos on my channel as well - all with Litchi - and hopefully more soon weather / temps permitting:
Mission Hub - Litchi