Replace 6100 IGP with 8800 GS for $62 (non-gaming rig)?

I'm building a new kit and it comes with nVidia 6100 integrated, which I think will be adequate since i'm just using the box for video/photo editing (Adobe Photoshop/Premier Elements, etc), CloneDVD, and iTunes. I doubt seriously that I'll be playing any games, though it would be nice to be able to if I got a wild hair.

My questions:
1. given my use case, is it pointless to get a discrete graphics card?
2. I think I read that 8800 GS's take about 100w of power...does that mean it's always pulling 100w? Like burning a bright lightbulb anytime the machine is on...in addition to the PC's power consumption?
3. Anyone know how using that discrete graphics card power consumption plus machine compares to using the integrated 6100 plus machine?
4. Amazon has the 8800 GS on sale with $30 rebate for $62...then I have a $30 gift card so my end cost to "upgrade" to this graphics card over the integrated 6100 is only $32 (free shipping).
5. Since I plan on running WinXP pro, I'm not concerned with Vista Aero

Thank you in advance for any help/insights you may offer. If it helps, links to the 8800 GS and mobo

GRAPHICS CARD: http://dealnews.com/XFX-Ge-Force-8 [...] 43006.html

MOBO: http://www.tigerdirect.com/applica [...] =A455-2810

right you are...but i'll pose the same questions with another discrete graphics card. NewEgg has an ASUS HD 3650 512mb on sale for $40 after rebate...thoughts?

And I can't seem to find any benchmark data on that card...I don't even know if it's particularly good. Heck, you can plug in any other sub $80 graphics card that is on sale.

http://dealnews.com/ASUS-Radeon-HD [...] 42875.html