For your first pass, leave zerosp out, but remember it if need be. It's potentially very useful. However, since I am only discussing imaging of one channel here, there is some hope of getting it right. I have treated the channel adverbs, in particular, in separate adverb boxes. If you want to move the centre of the image from the observing phase centre, then set shift for the shift in x and y in arcseconds on the sky.
Positive values shift the image centre to the North and East.
For example, you may have a short ATCA configuration such as the 750 m configuration as well as the 6 km antenna. This leaves a very large gap between the spacings involving the 6 km antenna and all the rest. To image just the short spacings you could exclude antenna 6 with this adverb. Make sure you turn on the grid correction with dogridcr . The recommended function is spheroidal, for which these adverbs should both be set at 5.