bitcoind and rollntime support According to this page: https://en.bitcoin.it/wiki/Poolservers bitcoind's rollntime support is 'Supported, but not advertised'.  I am taking that to mean that it doesn't provide the X-Roll-NTime header that would advertise this support, but you can increment the ntime value to get extra nonce space and still submit found blocks after doing this.

Is this correct?  If so, what would be the max amount that a mining client can increment the ntime value?
If so, what would be the max amount that a mining client can increment the ntime value?


bitcoind will accept a block and push it out to the network as long as it is valid. Because of that, it's incredibly lenient. Quoting from bitcoin wiki:


  A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours


It almost never matters. Because bitcoind is a single-user mining program, it's almost always on the same computer as the mining agent. If the mining agent needs to get more work units, it doesn't use up extra bandwidth.