wanna be,
Welcome to Android Forums! You'll find that there's tons of very cordial and very knowledgable folks here on AF. The Guides and Mods are wonderful and take very good care of all of us.
Your best course of action is doing what you've already started: reading and asking questions. There's more than enough forums and threads to sate your thirst for knowledge and if you don't see if posted or find it by searching, feel free to ask.
As you've probably already seen, the Droid X forums are broken down into a few subforms:
Motorola Droid X - Android Forums
Droid X - Support and Troubleshooting - Android Forums
Droid X - Tips and Tricks - Android Forums
Droid X - All Things Root - Android Forums
You will undoubtedly find what you need somewhere in one of the above threads.
Now, to your questions, I'll throw in my 2-cents:
How to get the most from my Droid X?
Start with the "tip & tricks" thread above.
Do I need to "Root"?
Don't know if you "need" to, LOL. I rooted mine only after I was satisfied that it was safe to do so (I was already comfortable with the terminology, concepts, and had prior experience from rooting my Eris). What have I don't with this new found power: honestly, not much. Played with a few root-only apps and that's about it. I've found the X already very fast, feature-filled, and trouble-free. I have not themed, overclocked, or installed any custom ROMs since I didn't see or have the need or desire to do so.
That being said, you might very well want to and the best place to start is by checking in to the main stickied thread in the Droid X all-things-root subforum:
http://androidforums.com/droid-x-al...ide-updated-4-pm-eastern-time-11-10-10-a.html
Are there unsafe Apps? How do I avoid them?
I'm sure there are some and you should probably read and research a little before installing anything that doesn't look like its had a lion's share of downloads. That being said, Android does a pretty good job of letting you know of an apps "intentions" based on what permissions the app requests/requires when you go to download and install it. For example, let's say you go to download a game and the Market warns you that the apps requests/requires access to your call log, you might be suspicious and pass on that particular app. Caveat emptor.
Is it safe to download and try them indiscriminately?
I would check the download count, the comments posted by folks, and also reference and check on the other apps created / posted by the author. Reputable apps should be no problem. Again, "buyer beware" (even for free apps).
Do I need to take precautions to guard against identity theft, and or spying, if so what are they?
No personal experience here regarding that, but I would urge you to alway exercise good judgement when entering usernames, passwords, or personal information: i.e., know your app, its security and intentions, and never enter any such information over an unsecured wi-fi network (i.e., WEP is easily cracked).
I am more interested in efficiency and productivity than in the entertainment aspect of a smart phone or personal computing device.
I'm sure there's lots of great apps and tools out on the Market that can help you. I personally use the Citrix app for communicating with work. There's also Good for MS/Exchange email access (I don't use it but lots of folks at work do). Check out the Market or any one of the myriad of Android application sites out there to help you with your research.
Welcome to the world of the Droid X.
That's all I got. Hope it helps. Cheers!