New WD My Passport for Mac - questions!

Don't install any software that exists on the WD My Passport.

The first thing you should do with any hard disk dedicated to Time Machine usage is to erase it. That will obviate any concerns with incompatible or poorly written third party software. You will lose nothing, other than whatever exists on the brand new hard disk drive, which should be regarded as trash and disposed of accordingly.

Using Time Machine really couldn't be simpler. For step by step instructions read Mac Basics: Time Machine backs up your Mac - Apple Support. There are only two steps and one of them is optional.

The important part is to erase the disk first, using Disk Utility, as described in the last paragraph under "Use Time Machine with external drives". Do that.

Time Machine will back up everything on your drive unless you go into its Preferences and Exclude folders. Just back up everything and you won't have to worry about manually copying files.

I know of no issues with Mavericks or Yosemite. I have the same WD drive as you and it's connected to a Mac Mini running OS X Server 2.2.5. Each Mac running OS X Mountain Lion or Mavericks or Yosemite are backed up to the drive under THAT Mac's machine name. So no conflicts and each client Mac can extract/restore any file they need from the WD drive.

To use Time Machine, just launch it from System Preferences and select the back up drive from a list of available back up drives. You can exclude any folder you want. If the Exclude list is empty, all files will be backed up. You can add additional files to the WD drive outside of your Time Machine back up folder. But why would you when you're backing everything up? 🙂

Yes, makes perfect sense.

So it won't automatically download anything and install?

No, certainly not, not if you use Disk Utility to format it first. That will erase everything on the new hard disk, and is the first thing you should do.

Disk Utility is in your Mac's Utilities folder. Find it by selecting Go... > Utilities.

There is more to your question that I did not completely address:

... I am looking to do a Time Machine, then drag over various documents, my Music folder, iPhoto Library, Mail exports, and a few other things.

After you perform the Time Machine backup, erase your Mac, and reinstall OS X, don't plan on dragging and dropping anything from the Time Machine backup volume. Time Machine isn't designed to work that way. If you do simply want to copy files and folders to the backup device, and drag them back after you erase the source volume, that's OK too. You don't need to use Time Machine for that purpose.

For Time Machine, follow these instructions:

• Create a backup of your existing system, and verify that it is complete. To do that read Mac Basics: Time Machine backs up your Mac.
• Ideally, create two or more backups using different methods, such as one Time Machine and one "clone", for redundancy. Neither method is particularly advantageous over the other for this purpose.
• Erase the Mac using OS X Recovery, and selecting Disk Utility to erase the Mac. That action will be followed by selecting Reinstall Mac OS X. After that, you will be prompted to migrate your essential documents including photos, music, work products and other essential files from the Time Machine backup.

To erase and install Mountain Lion read: OS X Mountain Lion: Reinstall OS X - Apple Support

To migrate your essential documents read: OS X Yosemite: Transfer your info from a computer or storage device and follow the procedure under Transfer info from a Time Machine backup or other storage device. The procedure is identical for Mountain Lion.

• When doing so, select your previous User account but do not select "Applications", "Computer and Network Settings" or "Other files and folders". De-select those choices.
• Subsequent to using Setup Assistant or Migration Assistant you will need to reinstall the essential software you may require. Install software only from their original or otherwise authorized sources, and omit all non-essential software.
• Printer queues, network settings and other preferences found in System Preferences will need to be re-created as well.

... my plan was to do Time Machine as a safety, just in case I realize I forgot something imperative, but really, start completely fresh and just load in the things I use regularly:

That's a fine plan. Time Machine merely provides an additional option in the event you forgot something.

The indented one.

It's not an absolute requirement, but I suggest using a simpler name than "My Passport for Mac". It's childish and insipid and illustrates the same Western Digital cluelessness that resulted in them distributing software on their drives that caused the problem you originally expressed concern about. It goes without saying it's yours and it's your Mac. Give it a name that makes sense to you, like "Backup" or something equally descriptive.

Another reason is that space characters in a Time Machine backup destination name caused problems in the distant past. That's no longer a concern but why ask for trouble.

Sure, ask away.

Thank you for your kind words. I'm not always available but I check this site every few days, if not more frequently. I rely upon email notifications when someone replies to a thread, but there were delays of several hours today, and there are rare occasions in which that feature doesn't work. So, there might be a delay. There are plenty of other knowledgeable participants on this site though, and some of them are literate.

There are many backup strategies, and Time Machine is only one option. The most important factor in a backup strategy is to have one. If you can imagine a circumstance in which your Mac becomes lost, stolen, or completely broken, and the prospect of that event doesn't result in sheer panic, then you're probably OK.

Once you have the Time Machine backup, if you find you need another application, you can restore it.