If you go down Lena's romance route you do lose one or two sex scenes I can't quite remember. But, she eventually tells you that she is okay with Cath sleeping around since she can't really match Catherine's sex drive, so her route is pretty much poly.
And about the backgrounds, we feel you! We set aside a bit of a budget and hired a part-time artist to just work on backgrounds for us, so expect a bunch more to come in the next few months!