I'm not sure if you've already figured it out yet or not, but although the bootloader is still locked you CAN flash at least the Hyperdrive ROM, and theoretically any other ROM based on the stock ME7 kernel if you use SafeStrap. I posted in the root thread with links to the threads you need to do it. [HOW TO] Root your Verizon Galaxy S4
For those who are rooted but no recovery. Try Philz Touch Recovery. There are a number of issues with trying to install TWRP as your custom recovery on S4s. Philz recovery is not as "simplistic" as TWRP in that it is much more customized with a lot of options that you don't have with TWRP. However, it has all the options you'll find in TWRP, just layed out in a different manner. Google Philz Touch Recovery and you'll find the link. I have the Developer Edition of the Verizon S4 and that is the only custom recovery that works on my phone, hope it works for you guys.