Ranadok

I think they only put them in when there's a long period with no captions. Usually at the beginning or end of a video, but I've had them during a silent/dialogue free scene in the middle of a movie before.

I went and checked, Tuvok specifically says it'll take several hours before they can send Voyager home (though not specifically that it needed to charge). Here's the exact line:

TUVOK: Captain, I can access the system to send us back to Federation space, but it will take several hours to activate.

They'd have to prevent the Kazon from damaging or taking over the array for quite some time before they could leave. I can understand why Janeway would make the call she did, given the risk of attempting that, but also can see why she would be tortured by the what if...

Wasn't there some line about how the array needed several more hours to charge up before it could be used to send a ship back, and the Kazon would have taken it by then?

That's not actually true (according to Wikipedia and a few other sources, at least). The 'blood is thicker than water' saying has been around for centuries in various forms with the current meaning, and the covenant/womb variation is relatively recent, and mostly stems from a few books that claim that it's the 'real meaning' without sources or proof.