You might want to think of signing up for Phoenix Pick's newsletter. They give away a free e-book every month and their catalogue is mostly older reprints (and DRM-free), so they're probably closer to what you want.
Their current freebie, the sf/fantasy
The Arm of the Stone is pretty good and fairly "clean" (maybe a bit of mild swearing I didn't notice, but not much more suggestive than mid-level Heinlein), but is kind of philosophical built around overturning a corrupt world order, so I don't know if that counts towards your points 2 or not.
They're having a 50% off with coupon sale (code in the link above) which ends today, and one you might want to pick up is L. Sprague de Camp's
Lest Darkness Fall, which is a time-travel classic. de Camp was an old-school writer and this was written in 1949, so I think it'll fit in perfectly with your no explicit sex/swearing requirement. Though technically it may have an "agenda" (i.e. preventing the Dark Ages).
They've also got more old-school stuff by Edmond Hamilton and Leigh Brackett, and I've just read and can also recommend Paul Cook's
Fortress on the Sun, which has very, very low incidences of swearing and sex mentions (there being a reason for the lack of the latter) and is a pretty well-written and interesting sf/mystery set in a futuristic prison camp where things are not what they seem.
Michael Flynn's
The Forest of Time novella was also "clean" on both counts, though I can't vouch for the rest of the stories in his collection. But they're mostly older stuff and probably wouldn't be any worse than late-era Heinlein.