Coming from an amateur like me, I think you've got a good setup. I had a 30D with the 18-135 and 55-250 as my first foray into the DSLR world. I found the 55-250 was too much 'range overlap' with the 18-135 and used the 18-135 95% of the time. The 70-300 looks like a more comfortable range overlap and gives an extra 50mm 'reach' when needed (80mm extra on the Rebel line).
I also noticed you've dropped the 8mm fisheye lens from your list. For now, 18mm should be wide enough for most of the wide shots you'll be taking. Perhaps you'll want to rent or borrow a friends 8 or 10 mm lens to see if it's what you'd like to own later on.
Use it for a while and you'll find out what kind of photography you tend to do most, and may discover you'll need different lenses to get the most out of your picture taking.