you should find the answers in the diva reference manual...
but as i recall:

Rewiring: means the LVS "rewires" errors it enconunters to complete the LVS. Its better to have this ticked. As a result you often get LVS layout errors of "merged net" which denotes the tool had to merge nets in the layout to match the schematic... ie you forgot to connect a net in the layout

Device fixing: stops the tool from rationalising devices or allowing permute rules on circuit components you fix. Not needed to tick unless you which to preserve for layout things like parallel/series resistors, exact matching of MOS no.fingers/wtotal etc.

Create Cross Reference: you create a cross reference between schematic and layout for a device or net. not
needed unless you have problems the tool can't resolve, typically involving circuits with loads of symmetry and loads of identical circuit paths...

Terminals: terminals (pins) are used as correspondance points between schematic and layout. If you names the pins in layout and schematic the same, then you should have this ticked.

cheers
aw