I love my toggles for WiFi, data, sync, Bluetooth, brightness, etc. I use widgetsoid because I can have my toggle bar in my notification drop down, always accessible.
WiFi uses tons less battery, so whenever you can use it, do so. Your phone will still do everything except picture/media text messages (need 3g or 4g for that) but if you get a pic text or want to send one, just toggle on data and you're good to go. Regular text messages work fine without data or WiFi on.
2 or 3 bars for data is not that bad. The status bar widget uses less bars for better data than it used to. If you go into settings> more... (under Data usage)> Mobile networks> Network type & strength you will get the actual strength of your data. Anything under -90 dBm is pretty strong, -90 to -100 is so-so, over -100 dBm is pretty weak.