There are upgrades out there that will allow you to view HTML emails on your Verizon Curve. I have a Verizon Curve and I recently installed OS 4.5.0.51 on my BB. This version is compatible with CDMA. I recommend upgrading, but not if you don't know your phone to well of if you're not that computer/BB savvy.
And I'm not sure about you're other question. There really is not that much of a difference between Desktop Manager 4.3 and 4.5