1. Neither you can use two different measures on color marks together nor one dimension and one measure on color marks.
You can try something like this to make your label more visible, click on your label and drag it up/down manually to set the position, like I've done for highlighted labels in below screenshots.
2. Did you mean to say annotation? Follow the link for more info
Let us know if this help.
Thank you. The drag is what I was looking for. I didn't know you could drag it out. For #2, annotate works but I was hoping to avoid manual entry. We have a bunch of waterfall charts to generate and wanted to drop the data in and create charts automatically. Thanks!