1. Juice Defender and Go Power Master works well only if you are using cellular data regularly, or is connected to WiFi the better part of the day. Otherwise they're little help. I tried Go Power Master and while the widget and profiles are nice, GreenPower and Juice Defender are way better options.
2. Since you are on JB, both Nova Launcher and Apex Launcher are way better options that Go Launcher. Smoother, faster and less bloated in terms of RAM usage. However they have features which work only on paid versions. The great thing about Go is that it's completely free. And they have the best Calendar Widget ever.
3. I prefer Boat Browser over Dolphin, but again prefer Chrome over both. Chrome only works for ICS and beyond. It syncs completely with your Chrome on PC, sending over bookmarks and passwords. You can also manage your bookmarks on a PC and it will reflect on the device. Also, the "other devices" section on Chrome for Android is a nifty little feature you may come to love.