A paper published by Niels Furguson Collision attacks on OCB indicates that processing large amounts of data (somewhere on the order of $2^{32}$ 128 bit blocks) with a single encryption operation (same key and nonce) makes it probable that an attacker could create a modified cipher text that would generate the same tag as a the original cipher text (pass authentication) and decrypt to a different plain text.
The probability of the necessary X collision occurring
$$(m−1)^2 2^{−128}$$
appears to be related to the block size of the cipher. In the paper a 128 bit cipher (the size originally recommended in the OCB specification) was used for all the probabilities cited.
Another surprising property observed is that using larger tag lengths increases the probability of a collision occurring.
My primary question is: does using a larger bit size cipher (say 512 bits) with a small tag size (say 64 bits) decrease the probability of this collision occurring? And if so does it decrease it enough that more than $2^{32}$ blocks of data can be written with less then a $2^{-64}$ chance of message forgery?
Niels advises against the widespread use of OCB; is this the consensus throughout the cryptographic community?