Okay. First, don't worry about the reset. It won't harm anything on your iPad. It's the same as a reboot on a regular computer, so all it does is, well, reboot the iPad. It doesn't mess with your settings, apps or anything. So, I still recommend you try it.
Also, one thing - what version of iOS are you running? The most current one is 5.0.1, but you type 5.0. Do you mean you have 5.0 loaded or are you just dropping the last part (and you have 5.0.1 loaded)?
Now, let me give a little disclaimer here: I have NO idea why your iMessage isn't working right. So, all of my suggestions to follow are things that I would do if I had the same problems. With that...
1) Try a reset of your home router. They all vary - but most can be reset by turning them off, unplugging them for about 5 mins, replug it in and then turn it on.
2) Try to forget your home WiFi. Go to Settings > Wi-Fi Networks > and press the arrow next to your WiFi line. At the very top is the line "Forget this Network." Press that line. Then, once your network is gone, re-enter it and see if that helped.
To be honest, I believe it's your WiFi connection (or the lack of it). Unfortunately, I don't know of any other way to fix it - I'm out of options here.
If any of these suggestions don't work, I must say you probably should restore the iPad with a "fresh" version of iOS 5.0.1. Yes, a pain in the ... knee
D), but so is not having your iMessage work.
So, try the above. If that doesn't work (and no one else can think of another fix to try) - I suggest a restore. We can help with that...
Sorry I'm not helping that well. Here's hoping the above will help.
Marilyn