Just thought I'd post some of my speculation on these items:
Plasma torpedoes are, in legends, designed for stripping shields. I suspect these will require the target lock to be spent and work like an ion cannon: if the attack hits, cancel all hits remove ALL shield tokens.
Adv. homing missiles are less damage dice, range and cost. I suspect that they will continue to require the target lock but not remove it, as well as the target not using evade tokens. However, for the trade off and range, I would expect an additional effect on top of this:
Spend the target lock to convert all misses to hits
Target may not reroll defender dice or spend focus tokens
Target reduces defence dice by one to a minimum of zero.