It should be emphasized that experts should start recommending that every single person in the world obtain their own effective (preferably elastomeric) respirator as soon as possible. This would eliminate any supply chain issues and most (and all with a good monitoring system) GCBR-type pandemics. As better respirators are developed, people with the older kind would be encouraged to upgrade.

Better examples discussing masks are the posts about elastomeric respirators here and here. Unfortunately, almost no policy maker seemed to have listened.

Rather than focusing on ventilation, I suggest thinking about recommending the voluntary use of respirators (preferably the elastomeric kind) instead. The problem with ventilation (even if it was theoretically 100% effective) is that it's only as good as how it was setup and maintained, and during a dangerous pandemic, I wouldn't trust any of these external systems to function properly.

Unless you have a reason to think otherwise, those methods of transmission (except for aerosol transmission) don't seem capable of spreading a contagion rapidly enough to end civilization. This has been discussed in other comments.

Why do you think fomite transmission is still worth considering?

Yeah, there were two groups that studied how rhinovirus is transmitted. One group was from the University of Virginia and found evidence of only fomite transmission. The study you cited is theirs. The other group was from the University of Wisconsin and found evidence for only airborne transmission. The Wisconsin group "...argued that the high rate of transmission via the hands in the Virginia experiments might be attributable to intensive contact with fresh wet secretions produced by volunteers who essentially blew their nose into their hand."

cause maybe thousands of deaths.

Don't you mean millions of deaths?

I'm confused about the distinction between fomite and droplet transmission. 

From what I've read, fomite transmission must involve surface touching, whereas droplet transmission must involve droplets, which are expelled by coughing or sneezing, directly landing (like a bullet) in your mouth, nose, or eyes without any extra contact or touching.

These methods of transmission seem so implausible (how many people actually sneeze or cough directly in someone's face?) to be major causes of spread that it's hard to believe that no one seemed to have performed definitive experiments to test these ideas for many decades. On the other hand, even seemingly definitive experiments (like the rhinovirus study) don't seem able to shift expert opinion. In the case of rhinovirus, maybe one experient isn't enough, but then the question is why no one seems to have been interested in replicating it.

it's certainly not impossible for non-respiratory pathogens to achieve rapid global spread.

I can't think of a plausible, non-science fictional way in which this would not be impossible.

If you can but prefer not the mention it publically due to infohazard concerns, please send me a PM.

In the context of this discussion (the post is about GCBRs), it should have been clear what I meant by that term.

Also, it can be claimed that a lot of things are "pandemics" like TB and antibiotic-resistant bacteria, but what is usually meant by the term is rapid, global spread (within weeks to a few months at most) of a deadly pathogen.