Variable access priority

Design considerations:

Setting a single priority value for all of the permissions created by the module is enough for my use case, but a more granular approach could be useful for some users. As I see it, we have many options, but could probably only choose one:

1. Single priority value for module.
   • Easiest to implement
   • Easiest to use
   • Not very versatile
2. Per content type priority value.
   • Easy to use
   • Slightly more versatile
   • Problematic if there are too many content types
3. Per node priority value (with UI on node/nid/flexiaccess).
4. Per user priority value (with UI on user/uid/flexiaccess).
5. Per grant priority value
   • Basically exposes a DB column.
   • Extremely granular; anything is possible.
   • Hard/impossible to use if there are too many nodes and/or users.

If it's too broad, the module becomes less versatile (which is bad, because it leads to more modules being created with similar purposes).
If it's too granular, it becomes impossible to use on large sites.
Could the above be combined, or made configurable somehow?

Here is an implementation. It contains:

1. Single priority setting for the module.
2. An easily expandable "Bulk operations" menu, with two useful operations included.