Pardoned units are some 5% stronger than their unpardoned counterparts and they use half of the rum.

You get more units pardoned by

1. holding more Presidios,
2. raising your Presidios to higher levels,
3. grouping your Presidios,
4. pearling pardons cost down to 50% of the original values.

What are the 5 TOP TIPS for an individual captain to seek to attack and hold an unclaimed Presidio? 

And what do I gain once I do that? 

And, how do I sense if others are trying to attack my Presidio? 

Where on the map should I search for a Presidio, does it make a difference, are some areas on the map less likely to be scanned for Presidios so that I can be safe there?

NavigatorNY said:

What are the 5 TOP TIPS for an individual captain to seek to attack and hold an unclaimed Presidio?

1. Start your own brotherhood.
2. Be filthy rich.
3. Keep buying all the rubies you can.
4. Keep reviving/buying units.
5. Stop all social interactions.

NavigatorNY said:

And what do I gain once I do that?

What I wrote in the previous post, plus "territory", which is a cute little number that doesn't mean a thing.

NavigatorNY said:

And, how do I sense if others are trying to attack my Presidio?

If you are an individual captain holding a Presidio, they will try (and probably succeed).

NavigatorNY said:

Where on the map should I search for a Presidio, does it make a difference, are some areas on the map less likely to be scanned for Presidios so that I can be safe there?

When in the map, click this:

Then attack someone's Presidio, conquer it, and defend it.

Presidios are usually a joint effort of the members of strong BHs, so I wouldn't suggest you go at one alone, unless you really can do what I listed above. The 5 item list probably sounds a bit sarcastic, but I think it's spot on. And even if you do all that, I'm still not utterly convinced you'll be able to pull this off. Good luck if you try, though. Honestly.