1. Firewire is not this important. There are devices out that have only firewire but do you own one of those ? If no, it is not needed. Most newer things can be bought with USB connectors and worst case just buy a pcmcia firewire card.
2. Same here, do you have digital media ? And even if you have them you can always buy an external reader or a pcmcia adapter for cheap. I would not make this a main criteria.
3. smallest number is 1 but it needs to be USB 2.0. You can always for home usage buy a hub. I would personally prefer 2 but with my laptop I used the second one like once in the last 3 years. Worst case you plug one cable in and another one out. Floppy drives are basically not needed much anymore, I can't even remember when I used mine the last time. Rather get a CD burner or a DVD burner.
4. except for gaming shared vs. non shared won't matter. What do you plan to do with the laptop ? If it is word, excel, internet browsing etc. then it really is irrelevant.
5. You won't need a Gigabit network card. It really does not matter this much and consider that e.g. your internet connection is maybe 10 Mbit the most. Gigabit is still more used on the server side and for clients only if you shuffle HUGE amounts of data around (e.g. CAD drawings).
But judging from your questions you miss the most important issues.
First, what do you plan to use the laptop for ? Mainly at home or travel a lot with it ? How much is weight a consideration ? With laptops reliability is a very important criteria since they can break a lot more often then a desktop.
Also I would strongly recommend that you get some type of backup solution (external USB hard disk, CD burner, DVD burner, ...).
Honestly with most modern laptops speed is faster then what most people would use it for.
I buy based on reliabilty, size of the laptop and durability. I saw laptops falling apart after 6 month on the road with some of our sales people.
Also if price is a consideration you might want to check
www.techbargains.com
once in a while to see what deals are out.