[Inconspicuous and choosing targets]

Further question regarding Abrown’s post RE: inconspicuous. 
 

if a MagnaGuard unit with the range 2-4 rocket heavy weapon is at range 2 of an enemy R2-D2 with a suppression and Atleast range 3 of any other unit, is that MagnaGuard unit forced to attack another unit using the rocket only or can that MagnaGuard unit split fire, attacking R2-D2 with their base range 1-2 weapon as a secondary target? 

[Ground Vehicle unit blocks LOS for other minis in the unit]

A specific example would be the droideka. Can I please confirm that a ground vehicle unit like the droideka can give itself cover if its silhouette obscured the other mini in the unit?