[RedRover]

I think the AI would do a lot better with blood-hunting nations once it is capable of building more forts.

Perhaps some of those testing Dom3 might weigh in with an opinion? Is such an effect observable?

A default 25 PD for a province with a fort seems reasonable to me (possibly moddable by fort type and/or base nation); the trick would be to integrate this into the build/recruiting algorithm in a reasonable fashion.

One lump to PD 25 may be too much (325 gold), but maybe an initial build to 10 PD (55 gold), then +5 PD/turn to 25 (costs 65, 90, 115 gold, respectively)?

The simplest way might just be to add the default PD cost onto the fort cost and delay building until everything can be paid for at once. Of course, different approaches might be combined.