Nice to see how this tank is coming along. Yes, I agree that the filter should be moved to behind the plants (and move the thermostat over a bit so it's not visible)- you don't really want a filter to be the focal centrepiece in the tank lol - so if possible hide it or hang it on the side rather than placing it central. You're lucky to have a lovely bushy plant you can hide those things behind so might as well make use of them.
Yes, more plants I think. Try to graduate them so that you have large at the back, then medium, then small. The plants you have are super btw and I love that bogwood in the middle.
Regards, Athena