You should only root your device if there's something specific you want to do that requires root. If you're happy the way things are, don't mess with it. There are some neat things you can do with root, but most of them are primarily interesting to technically minded users. There are a few exceptions, sure, but unless you find an app that makes you say "I must have that and there are no alternatives," you're probably better off not rooting.
As to your specific questions:
1) Yes, rooting will allow you to add the Google Play Store to your phone. This is sometimes nice, but not necessary. Most of the big, popular apps are available on both markets.
2) Rooting may, or may not, wipe your data. Anytime you unlock the bootloader, all user data gets wiped. Some devices can be rooted without first unlocking the bootloader, and some can't. I haven't researched the various methods of unlocking a Fire lately, so you'll have to do your own research on this. Unless you're very sure that the rooting method you find does NOT unlock the bootloader, though, assume that it will wipe your data. Of course, you can back up most of your data, paid apps should be downloadable again for free (assuming you have access to the account that purchased the apps in the first place), etc, so a data wipe is not the end of the world.
So! Should you root? Probably not. I'm happy to answer questions or go into more detail if you'd like, but that's my recommendation for the time being.