Directors: Dave Fleischer was credited as director on every single short the Fleischers made. It should be noted however that, according to the account of animator Grim Natwick, Dave was not a traditional director in the same hands-on sense as, say, Chuck Jones from Looney Tunes. While he did not plan the layouts, he did plan out the key poses, timing and voice recordings, and his impeccable gag and story sense are unmistakable hallmarks of his influence on the cartoons. Unfortunately, when he began having to direct the two feature films the Fleischers made, he had less time to oversee the work on the cartoons, resulting in some animators directing in his steed.
Public Domain: By sheer serendipity – Paramount just didn't care enough to renew back when it mattered – at least 68 of the sound Fleischer Studio cartoons have fallen into the Public Domain, including some of the classic Popeye and Betty Boop shorts, and their Gulliver's Travels feature is public domain as well. This is why those giant video collections of random Golden Era shorts you find in dollar bins tend to have a lot of Fleischer material. All, or at least many of the Out of the Inkwell films are presumably public domain as well.
This does not, however, apply to most of the characters themselves. For instance, Popeye is still – as he was then – owned by King Features Syndicate (E.C.Segar died in 1938, so his copyrights would normally have expired by now; however, KFS holds trademarks on the franchise), same with Betty Boop.
A model sheet for the Superman short "Japoteurs" indicates that it was in pre-production at Fleischer Studios right before it became Famous Studios.
If these sketches are anything to go by, the Fleischers were considering making a Screen Song about the song "Mysterious Mose" that mixed animation and live-action. It was scrapped, but the song later became the basis for a Talkartoon short.
Before they became famous, future comic book artists Bob Kane and Jack Kirby had briefly worked for the studio doing in-between animation on Popeye and Betty Boop cartoons.