[YZF]

The max input size is for one message. It's effectively the "block size" for RSA. You can send multiple messages using a single RSA key (and in fact pretty much everyone does that, otherwise you'd need a new public key for every message). RSA is a complete crypto system, you don't need any additional ciphers. You do need randomiziation (e.g. random padding).

[YZF]

For the sake of completeness, one such construction where RSA is used as a cipher is OAEP (Optimal Asymmetric Encryption Padding). Beyond being slow it has some other inefficiencies but that's another story.