When in razor tool mode, marquee could be possible when holding down left mouse button.

@4977934 Jaber is correct, in point, our point, lift / extract is the way. All of these have keyboard shortcuts. Keyboard shortcut for "add edit point" will let you avoid using the razor mouse tool altogether. A keyboard shortcut for "select clip under play head" will let you choose a clip you've cut and then lift/extract/delete key to get rid of it.

Point is: you will likely be faster and more accurate with keyboard shortcuts than you will be with a mouse.

You can set In-Out points and use Lift or Extract, it's more precise than dragging by hand. If you want to delete whole clips just Delete or Ripple Delete them.