I would love to see pics of the congos, they are my favorite fish.
How many congos do you have? They are really shy when you have a smaller number, even at 5 mine hid all the time. In larger numbers when they are content they are awesome, not just in attitude but in colour.
Most plants don't mind a hard trim, just leave a few leafs on the bottom half. If your really unsure do what I do, I trim one out of the bunch and see how its grows before chopping them all