Upload & Sell: Off
I've had my D300 since right around release date. I use 133x Transcend cards - cheap, never had a failure (knock on wood) and transfer speeds aren't a big concern on the camera.
I also have had the 18-70 for the same amount of time. It's such a great little lens. Is it pro-caliber? No. The build quality is a little cheap, no VR, variable aperture... but it's light, pretty sharp, compact, and inexpensive. Use the heck out of it.
I would skip the mega-zooms. If you want a telephoto, the 70-300 VR is a great compliment to the 18-70, while also not breaking the bank or your back. Other than that, figure out where your lenses are not satisfying you before you start upgrading. I mean, the 17-55 is a fine lens, but if your problem is that you really like the 30mm focal length but you want to take pictures in very low light, the 35mm f/1.8 will give you more light for less money. I have a 50mm f/1.4 that I don't use much because I find it to be an awkward focal length on DX - I use my 35mm f/1.8 much more. Personal preference - shoot with your camera and figure out the focal lengths you prefer.
I don't use grips on my cameras. It's big and heavy enough as it is - but that's just personal preference.
Only thing I'd test is for dust on the sensor (so you know if you have to clean it), test all the buttons to make sure they work, and then shoot a couple test charts just so you know if the autofocus works. Test for dust by zooming your lens all the way in, manually focus to the closest setting, set the lens to the minumum aperture (f/22 probably) and take a picture of the sky. Dust spots will be evident.