I didn’t care.. if I was doing it I’d probably note down their coordinates before moving and change them back after moving.
Afaik only the legacy canvas in PCBnew (not the fp editor) atmo has got the option to exclude different things from a selection bracket.
Depends on who you ask really. Many ways led to Rome.
Both EEschema and PCCBnew can create Bills Of Materials for the ‘things’ that they know about.
You can place schematic symbols in EESchema that will not appear in PCBnew.
Same thing for things you place in PCBnew only.
So depending on your workflow and organization a lot is possible (luckily KiCAD isn’t nailed down in that regard and leaves a lot of choices for the user).
Re “atomic parts” and personally vetted libraries.. it looks overwhelming at first, but once you wrapped your head around 2-3 things you’re good to run
EESchema and PCBnew handle libraries different at the moment, deal with it. PCBnew’s way is the future, but for EEschema it’s a while away
for atomic parts (symbol + footprint + IDnumber/etc.) you have to run your own libs and maintain them
there are 3rd party scripts that will be able to get you BOMs with prices from the major distributors if you do 1 & 2 right