1. You can update most of the metadata fields that LRCC shows, e.g. title, caption, copyright, location (all 4 fields), and you can also edit the capture date. You can't add or change the GPS co-ordinates, nor can you change the filename.
2. No, not yet....though you can apply changes to multiple images at the same time.
Hi you create a preset buy right click a file..... metadata presets>edit preset...... fill in only the fields you want in every file and you must tick all boxes to the right of the fields you filled in. then in the top header bar click in it and select to save a new preset. Presto !! you have a preset.... now to apply to your files ...Library view select all the files you want to apply metadata to....then....metadata panel on the right .. top of the panel you will see preset.. select your preset .. hey presto ! all files will be written with copyright, address, email, business name etc..
Nice answer, but unfortunately it refers to a different product (LR Classic). This thread is about the cloud-centric version of Lightroom (Lightroom CC). Lightroom CC does not yet support metadata presets.
I have not installed the web LR, I had no idea they were different.