I bet the super red just needed more macros too, unshading will definitely help
Dont overthink flow. If as you say thats the only plant not swaying then you have more than enough
Im diggin the fern, great plant for the back wall. Dutch master Willem Van Wezel has used narrow leaf like that in some of his tanks. As it fills in you can just slide it to wherever the empty spaces are
Where's the Xyris? Thats a good choice for the AR spot, in front of something green and tall enough to be a backdrop for the downoi