Does rsa-oaep provide or not plaintext integrity in addition to confidentiality?
RSA-OAEP does not provide "plaintext integrity in addition to confidentiality". ​ By the definition of PKE, anyone with the public key can encrypt whatever plaintexts they choose. ​ In particular, encrypting "a symmetric session key appended with a hash or eventually crc value for insuring integrity" doesn't help. ​ To get integrity, there has to be something [the honest party knows which the adversary doesn't know] or [the honest party can do that the adversary can't do].