If peDbGridType is gtAutomatic, will the tWebRow array consist of ALL qualified rows (that meet the list's DDO constraints) or just those rows displayed at the time?
Just the displayed,

Would it be best to set peDbGridType to gtAllData, so the weblist is assured to be complete as displayed?
no rule ! it deppends on how many rows are we talking about... and the filter complexity you will be using.