Currently, Hue scenes cannot be called from HE. However, there's no reason you can't recreate said scene in HE using the Groups and Scenes built-in app. For a single lightstrip, I would just set the device properties instead of using an actual "scene" unless you are doing things like changing the color and/or color temp on it.
Beyond that, the rest is pretty easy with a couple of rules in Rule Manager. The first rule, light on from dusk to dawn is easy (so I didn't include an example of that). Personally, I would use Simple Lighting for it, but that's just me.
This is the motion lighting rule. I used a triggered rule. There are various ways you could do this, but I went for the straight forward way. When motion is detected and the lux is below 100, then turn the light up to 30%. When motion stops, it dims the light back down to 5% over 2 minutes.
This is the stairwell motion alert/rule (I don't have a stairwell, so I used my kitchen sensors lol). If you want to use Alexa as a notification device, I'd recommend setting up either the EchoSpeaks app ([RELEASE] Echo Speaks) by @tonesto7 or the AlexaTTS app ([Release] Amazon Alexa Text to Speech (TTS) v0.5.4 - Direct Integration (USA, Canada, UK, Italy, & Australia)) by @ogiewon. Both are really well written and perform well.
