As for locking layers, one can do: right click the layer > lock/unlock > lock all but this. A 'reverse' option would also be nice, to you know, set back the original 'state' before locking any or almost all layers after done doing the editing or selecting (not talking about undo commands of course).
I would add it as a suggestion, like many others, but they make you jump through waaayy too many hoops it's ridiculous. You need to go to another website, register there, figure out how that website works, and then study what is almost a book worth of 'guidelines' on how to post a suggestion or bug so it doesn't get immediately closed for being 'incomplete', and if finallyyou get it online, then maybe, just maybe if you're lucky they will take a look at it if it gets enough upvotes!!
You pay serious money to these guys on SUBSCRIPTION basis and still they don't make it easy for you.