I am going to respond properly later but here at some photos of the tank face on. I also have two air stones running at either end of the tank.
Great stuff! No way that tanks needs stripping down and starting again in my opinion.
Surface agitation looks good actually with the HOB waterfall and dual airstones, so you're fine there.
I really think a better (larger quantity) water change regime, and stricter/more regular fert dosing and you should be fine longer term. Adding some more plants would help also (50-100% increase in plant mass I'd say), if it doesn't deviate from your intended aesthetic. Most of the algae should be easy to remove manually (an old toothbrush helps).
I'd also love to know how you managed to get your Mollies to pose in tandem like that! 😀