Personally, I find the danger won't be the production volume (which IS an issue, to be sure, not denigrating that fully) but the public narrative.
If the Elio has any sort of problems, be it poor safety standards, overall build-quality, ETC; people are going to latch onto that and it will be a shit-storm. Just look at Jalopnik... they look for any little negative detail (real or perceived) in order to piss all over the Elio. And three-wheeler trikes already have a history of failure about them and get labeled with crap stories (too many people still think the Reliant Robin tips as easily as shown on Top Gear, not knowing that the TG team did everything they could to make it tip over), so there's an already built-in negative stigma.
So not only is the final autocycle going to have be phenomenally well-built, but their communications team is going to have to be on their A-game in order to nip any potential negative stories in the bud. Because if they don't, people who want the Elio to fail WILL run the narrative and ruin any chance of Elio succeeding.
I look at the Tesla Autopilot death that just happened. Tesla were prepared for something like that, so when the unfortunate event happened, they were all over it. A lot of fire and brimstone building up, but they nipped it in the bud.
It's why although I can appreciate them giving 'first-looks' and 'test-drives' with the P4/P5, I really wish they'd hold off until the autocycle is 98% production ready... so we avoid what happened with the fender in NYC. Because if there's one thing Americans love more than a success story, it's a failure.
I can see them hitting their goals once the Elio is finally on sale and people see them driving. But it won't happen if Elio has bad word of mouth right out of the gate. They have to control the narrative or I can't see them succeeding.