When I'm on my phone, is there a way to get a notification that I have received a text message or email message? Right now, I have no idea if I get a text while speaking on the phone.
For your Tour, I don't think you can receive notification while talking on the phone.
With the CDMA technology, your phone can either receive voice or data transmissions at any one time (others please correct me if I am wrong). So if you are on a phone call, you are utilizing the transmission 'band' available and if you receive a text (also voice) or email (data) transmission those will wait 'in queue' until your phone is available to receive them. As you have a BB Tour, you do not have WiFi, which would be an alternate method for data (email) transmission to be received.
I suspect that your texts get sent to your phone immediately as soon as you hang up your call. Even if you had WiFi, this would not change as you are using the voice side of the transmission for your phone call.