Not sure what caused your green tint, and I have never used Nero before. It may have been some filter or something that got set in Nero at the time? Lightroom is part of the Adobe Photoshop Family, and it works hand with the other Photoshop products. Lightroom doesn't have some of the more advanced tools like layering and masking etc of Photoshop, so you can send an image from Lightroom to Photoshop, edit it in Photoshop, and once you save it and close it in Photoshop it shows up in Lightroom again with your edits. I don't have much need for those tools, so personally I spend about 95% of my time in Lightroom and only rarely ever need to send anything to Photoshop.