It’s totally up to you, whether you want to edit the originals or not. About the only time I ever use virtual copies is when I want to make a different edit of the same photo, (1 color, and 1 B&W for example).
To keep your catalog from getting crammed with unnecessary clutter, don’t use virtual copies unless you need them. There’s definitely no real advantage to editing virtual copies instead of originals.
One of the main strengths of Lightroom is that it is completely non-destructive. No matter what edits you make in Lightroom, you can always go back and undo them. If you decide that you don’t like what you did, you can go back and start from scratch.
To me, it would be sort of redundant to edit virtual copies. All your edits are already non-destructive, so you don’t have to worry about changing the original file.
I also definitely don’t recommend that you reset the picture after exporting. Why would you want to undo all your hard to edit the picture? Believe me, when you’ve gone through 450 wedding photos and edited all the ones that are keepers, you appreciate all the work it was to edit them! 🙂 There’s no real benefit to resetting all your edits. If 10 years later you don’t like the way you edited it, you can always re-edit it to suit you (remember, Lightroom is 100% non-destructive).
Feel free to ask more questions if I didn’t make sense, or if there’s something that’s still confusing. That’s what these forums are for! 🙂