Thanks, everyone! You've eased some of my concern.
BA seems to have good availability. I'm more worried about UA/LH to MLA (especially at the saver award level). There's so few airlines that fly to Malta. And I'd have to be able to get award seats both ways, otherwise I end up paying for a one way ticket, and they're so expensive I might as well buy the roundtrip ticket.
The other option is to just find award seats going to somewhere Air Malta flies, and then just pay for that segment to MLA. Air Malta doesn't seem too expensive (I think a few hundred dollars for a O/W LHR-MLA segment?). I tried doing some research, but I can't find if Air Malta has an interline agreement (right term?) for my luggage to go the whole way, so I may have to pick up my bags and recheck them for the flight to Malta.
bj2757, I understand what you're saying about the flights either being available or not. Maybe I'm just worrying too much. I think in the back of my head it feels like if I'm using miles for the ticket I'm more likely to get bumped if something goes wrong. Probably unlikely, though.