Replying to my own post here - if you want to skip the long version, I was successful in fixing this with zero response from Creality.
Since posting this, I have been able to successfully clear the blockage. I found this video and it was somewhat helpful - I heated the nozzle to 230 degrees as recommended, ten degrees higher than I had attempted on my own. Even then, I couldn't initially shift the blockage with the Bowden tube as shown in the video. I ended up using one of the smaller Allen wrenches included in the toolbox and using it as a ramrod. This was enough to cause the plug to finally dislodge - I managed to get two pretty big globs of chunky PLA to come out. After that, I used the Bowden tube to clear any lingering blockage.
After clearing the blockage and reassembling the printer, I was able to successfully print! I'm using some HATCHBOX PLA I purchased after many recommendations to not use the PLA supplied by Creality.
All told, it's been almost two weeks since I first reached out to Creality through chat, email, and Kickstarter comments. It's also been six days now since my follow up email, and this post took a couple of days to get approved. Between all of those attempts to get some feedback or assistance from Creality, I have heard nothing from them while they still tout their "24 hour" email response time. I'm beyond disappointed with their ability to meet their customers' needs in the timeframe they promise.