Alright, this album isn't really all that inappropriate - aside from two songs that there are clean versions for or you can easily just rule out. Just going to go through the tracks and address the inappropriate content they may have. Understand that despite there being a song or two about sex, it isn't necessarily crude or meant to be and rather artistic.
Aura - Devoid of explicit lyrics, though a specific verse has been found controversial among religious groups ("enigma popstar is fun, she wear burqa for fashion") and in two brief lines she sings "dance, sex, artpop, tech", but it doesn't particularly stick out and she never goes further than that.
Venus - Venus is somewhat obviously about sex (but what song nowadays isn't?) but there are no explicit lyrics other than "a--" near the end of the song. If you're bothered by that one little word, there's a clean version out there.
G.U.Y. - An acronym for "Girl Under You" that is mostly clean aside from the line at the beginning in which she briefly states, "Greetings Himeros, god of sexual desire!"
X Dreams - This song I would highly suggest keeping from your kids. It doesn't have any curse words but the subject of the song is beyond obvious and there are some minorly dirty words to be found.
Jewels N' Drugs - Another dirty rap track that I would also keep from your kids. The word "p---y" is used by guest rappers, among other words. The clean version doesn't do much considering the song is loaded with bad language and it is still pretty much audible even with the blurs.
MANiCURE - Clean. The subject of the song isn't dirty either.
Do What U Want - S--t is used once. Clean version is available and isn't even regarded as explicit.
Swine - A-- is used once, though not classified as explicit.
Donatella - B*tch is used in the opening line. Again, a clean version is available.
Fashion! - Entirely clean song entirely about just what the title suggests.
Mary Jane Holland - P--- is used once, but it isn't even classified as explicit nor does it stick out.
Dope - The f-word is used once. Very depressing and personal track. Clean version is available that removes that word from it.
Gypsy - Clean dance track.
Applause - Kid-friendly and almost a hundred-percent clean song. Some lyrics may seem dirty to those who are older (give me that feeling that I love / turn the lights off / put your hands up / make it real loud) but the actual meaning isn't dirty by any means.
Not very dirty as a whole, X Dreams and Jewels N' Drugs obviously are but those can easily be restricted (and are the worst songs on the album regardless) Good album as a whole with an occasional word. The subjects are no more inappropriate than most mainstream pop, though there are still some mature ones. Born This Way is much more clean than this and features better messages, so I'd probably suggest that for the younger group. Great album for teens 14 and up.