How can I make a filter to exclude someone who has a certain tag assigned to them? (or custom data field yes/no type)
For the filter part: different types of custom data result in different filter operators being shown in the filter configuration screen.  You can experiment with adding different custom types to see the effect on the available operators.

For your purposes, you could add an "Inactive" field of type Alphanumeric, Text.  In the view configuration for the filter you should then have the "Is empty (NULL)" operator option.  Configuring the filter with that will remove from your view any records that have something in the Inactive field (yes, moved, gone to college etc).

(NB 'text' is not necessarily the best choice from a pure Civi perspective but it will do what you need with Views.  If the "Is empty" operator becomes available on more types in future you might prefer one of those.)