Ctrl-V is to enter vertical visual mode. After selection use Shift-I to insert the text. It will look like you are only inserting in one row but after exiting insert mode, esc, it will apply the changes in all selected rows.

No Firefox for the browser? Really?

Are you using battery thresholds and keeping your laptop connected? There is a bug in ThinkPads, at least with my t480, in which the batteries get discharged over time but doesn’t get reported which causes the sudden power off. If you are using TLP I suggest you to either force a full charge or a recalibration to charge your battery properly. Also don’t discard the possibility of having a broken battery.