Hey there, I just happened to come around before the stream and had a moment to post.
Firstly I just need to say that it's been a lot of fun to be around and laugh at your reactions, random stuff happening ingame and cringe a bit at the gameplay
(nah that's fine, I'm just a person terminally glued to Insane difficulty)
As for the campaigns, I guess I can share a bit of experiences.
Generally speaking, mods rarely have functional voice acting in place. As for the gameplay, there is a quite noticeable trend in the old mods (that weren't upgraded much by now) that their gameplay is often seen as quite a bit tedious - not to offend the modders of old, but back then the idea of more content did consist in a significant part from more shooting, which was done by sending more enemy waves. I think it's a thing worth considering later on.
As for the list, a couple corrections. One, Solaris is a fully independent universe from Freespace. Basically the only thing it shares with Freespace is the engine. Which in no way detracts from the experience, of course.
Aftermath Reboot takes place 7 years after FS2... it even has a massive banner with that written lol
Aftermath Reboot 2 is known to have been... problematic with its balance. I think someone who has played both parts recently should stand up and comment on how both are feasible to play right now.
Also, your list mixes in a lot of different types of works. There are massive mods (Blue Planet, Aftermath Reboot, Ancient-Shivan War) that consist of similar amounts or more content than FS1 or FS2, and there's a bunch of minicampaigns (for example Walls Closing, or Eyebleach) that are only 4 missions long. And of course a bunch of things in between. But I guess the decisions will come up when you're progressively pushing through the content.
Another important part regarding mods is about copyright issues regarding their music. I'm not sure how that applies to streams, but I vaguely recall that for example, Vassago's Dirge music was at some point copyrighted which resulted in people needing to take down their gameplay videos, or something along the lines. Someone more competent in this regard would need to speak up but I'd like to mention this right now, to keep in mind for later.
As for different mods, remember that there are total conversions - which take place in a different universe than Freespace. Beyond the Red Line, Diaspora and Adversary are from Battlestar Galactica, there's Wing Commander Saga, The Babylon Project and something more that escapes me at the moment. There's also a custom universe of The Antagonist and Burning Heaven which both are quite interesting and even voice acted.
Also there are a couple mods that make significant changes to how you play the game as a whole. There's of course Trimurti because Shivans and gameplay more on instinct than anything else There's Bem Cavalgar, which I hear has a massive factor of resource management between missions and making tradeoffs. A couple other things you could try later on are SHUMPspace (a 2D scroll shooter) and Windmills (a strategy game inside Freespace). There are some mods that in some place give you control over a capital ship, too. Of course there's a bunch of other things you can try which I forgot or never known about.
Beyond that, HLP has a Discord server
which I would encourage you to take a peek at. There's a lot of activity in there, an actual announcement system for new mod updates, and I think you could count on some mod dev joining up to provide some developer commentary while at that.
Re: issue - try navigating to MediaVPs mod tile, extending the dropdown menu, hitting "Modify", marking all packages and letting Knossos download them. There's a couple of packages with cutscenes and I guess this could possibly help.