Not sure if your question about responding to individual posts was ever answered . But to respond you have to first make sure you are logged into this page . If you are each comment should have the word " quote " by the share logo at the bottom right hand corner . Just click that and the page will scroll down with the comment you are responding too and a box to type in your response . 

It depends on your ultimate goal as some players might be trying to obtain all the champions or at least the best . If that is the case here I personally would not sacrifice anything from that list . Then possibly work on making a few 4 stars from other 130 champions never sacrificing any champion unless you have more than one . 

Then at some point you might get a 5 star champion that you already have from the shards or from sacrificing 4 star champions .

Her main task is to remove all buffs and place 50% Decrease ATK and 60% Decrease DEF. Then maybe finish off survivors of your nuke barely clinging to lige, or remove some more buffs. Her A1 is for sniping in some fear or finishing off an almost dead single target.

I would advice two Speed sets and an Accuracy set, or even 3 Speed Sets. Preferably with *6 boots with Speed as primary stat.

Rarity of your gear does not matter nearly as much as the number of stars, primary stat, and the secondary stats rolls.