Vostro 1400: Questions about reinstalling XP drivers

I ordered my Vostro 1400 with XP pre-installed about seven months ago and just suffered a virus attack that lead me to a clean re-installation of XP—which went well. I have some questions about the process of re-installing the original drivers:

1) Does the order in which you install your drivers matter? Some seem to say so, and if so, then I am out of luck. I have installed drivers from Dell’s Drivers and Utilities re-installation CD at random.

2) I’m wondering if I’m missing any drivers. On the forums I see recommendations for a Touchpad driver, for instance, but my touchpad is working just fine. I’ve installed these drivers so far:

Audio:
-Knowles Acoustics IntelliSonic Speech Enhancement Rev: A07
-SIGMATEL STAC 92XX C-Major HD Audio Rev: A09

Chipset Drivers:
-Intel Mobile Chipset Rev: A02
-Ricoh R5C833 Rev: A01

Communication Drivers:
-Conexant D330,HDA,MDC,v.92,modem Rev: A00
-[whatever the stock Dell wireless card driver is called…]

Video Drivers:
-Intel GM965 Express Chipset Family Rev: A03

3) My Vostro 1400 came with a Drivers and Utilities disc specifically for an XP set-up, of course. When I load this disc, a menu of different drivers appears. A few of them have checks beside them, which indicates that such and such corresponding hardware has been detected on my Vostro…so far I have intalled all with checks except for the
Serial ATA Driver: Intel Matrix Storage Manager Rev: A02. I hesited to do so because I noticed that 1) Dell’s page lists this driver as optional; and 2) other guides seem to suggest there multiple SATA drivers are needed and must be loaded onto an install CD (such as by Nlite)…and I’m not sure what that means. Should I just install the provided SATA driver?

4) The only functional problem I’m having so far is with my media buttons. They work just fine, but when I lower or raise the volume the meter no longer appears on my screen…perhaps this is a software issue and can be solved internally. Any recommendations?

5) Is Dell Media Direct worth re-installing? Isn’t it just bloatware? I ask because while digging around I was surprised to find that it seems a lot of people like it.

6) I’m quite a novice, so is there anything else I’m forgetting?

Thanks in advance!