This tank is a couple years old now? Have you ever let your background plants grow vertical? And with only shrimp in there, why do you need the surface skimmer? Shrimp food doesn't leave protein on the surface IME. Its a nice scape, I like it.
Yup, tank is now a few years old and been through the paces...
The plants themselves have been through all different looks too... infact around 6 months ago the background plants would almost be at the top of the tanks rim, till i decided to keep trimming them back until they filled in at a lower height as you see now (since i wasnt a fan of the height due to it blocking flow of water)...
As for the skimmer, yes it is necessary for 2 reasons.
1) due to bio-film etc that does build up on the water surface (over a few days) which then traps the Co2 in the tank causing major Co2 build up...
2) it adds more flow to the tank keeping water circulated around the whole tank