Key cracking: Prefer many small texts over one large text?
Assuming perfect implementations and good block ciphers, it doesn't matter (for any of your questions).

As long as the underlying block cipher is good and has a long enough block length (e.g., 128 bits, as all versions of AES have), any good mode of operation has a security theorem guaranteeing security against chosen plaintext attack for a total of about $2^{b/2}$ blocks of data, where $b$ is the block length. For $b=128$, that's $2^{64}$ blocks, which is more than anyone could ever have time to generate or encrypt (or store).

All this applies to CPA security, which is an even stronger property than resistance to key cracking.