Anybody else think the tree looks artificial? the leaves look too regularly arranged and a bit plasticky to me. They're not needles so it's not a juniper or pine. I wonder what the source of the picture is.

There are a couple of mimosa-like pests in the Southeast, but the worst, and the one you may have, is chamberbitters (Phyllanthus urinaria). That's the one with the seeds underneath the sets of leaves. It's a real nasty, and if that's what it is, you're going to need all the luck I can wish you. Take a look at the attached page from Clemson, and then google it for more information. There apparently is a herbicide that works on it, but it's not Round-up, so you may have to look for it. Good luck. Here is a link that might be useful: Clemson page on chamberbitters

Scottish Bond is a pattern of installing the brick. Not the brick itself. If you don't like the color of your brick, there is brick stain available that can be applied to change the color. However, if you are looking to update the appearance of your home, I would start by painting the shutters and front door a darker, more contrasting color and replacing the leggy bushes in front.

It looks like a Gentiana. Possibly G. cruciata or G. saponaria. Can your friend get a pic of the entire plant and is it growing in a garden?