Here are some playtesting comments regarding my experience with some of the BRCS feats and associated skills:

Master Administrator - I've mentioned before that I revised this one in regards to seasonal domain maintenance. I have it allowing the DC for seasonal maintenance to be 10 + [1/2 x seasonal maintenance in GB). I've found that works well to keep maintenance savings within reach for a slightly longer duration. Normal DC's are [10 + GB maintenance], rather than 15 base. By the time characters level up high enough to make such a high DC, their domain expenses tend to be too high to reach without the Master Administrator feat anyways. This is especially true for landed regents with armies.

Also, this feat granting a +2 synergy bonus to all Administrate-based domain actions is EXTREMELY powerful. What regent in their right mind wouldn't try to take this feat as soon as possible? That's +2 to all Create, Rule, and Contest actions for holdings AND provinces! That's an enormous advantage for a single feat.

Similarly, Regent Focus: Rule Province has become another "must have" feat for landed regents. It grants +4 to ruling provinces, which is normally very risky (expensive) and difficult to achieve.

So here's what has become a bit too formulaic in my game: Every smart (read: competent, relative to the competition) landed regent takes Master Administrator and Regent Focus (Rule Province). A 2nd level character could then gain +7 to his/her Rule Province actions (5 ranks in Administrate = +1, +6 for the feat bonuses). Doesn't this ring of game imbalance?

Here's my suggested alternative:

Lower the advantages of the Regent Focus feat to +3 to the selected focus, making it the equivalent of the 3.5 Skill Focus feat. Alternately, make it +2 if you base domain action synergy bonuses on skill bonuses rather than ranks [see below].

Do away with the +2 domain action synergy bonus of the Master Administrator skill, but make it more useful regarding domain maintenance [see above]. Let it still give a +2 skill bonus to the Administrate skill itself, and the reduced DC for seasonal maintenance. This is quite an advantage all by itself.

Ranks vs. Bonuses: When calculating synergy bonuses for Domain Actions, give a +1 bonus for every +5 skill bonus in the key skill (rather than +1 per 5 ranks). This rewards talented rulers, and significantly raises the value of skill-enhancing feats. Talented rulers are ones who have important political attributes like Intelligence and Charisma, and who focus their skills in synergistic ways (Diplomacy is a prime example of one that can really stack up).
In my opinion, this is more realistic system that doesn't make things quite so level-dependent. Bonuses based on skill ranks are strictly limited by character levels, which is rather narrow minded and restrictive. Open up the system to talented young regents with "the right stuff," and Cerilia's competitive balance might be better represented.

Master Merchant is another "Uber-Feat" that needs to be toned down. +2 to all merchant and trade-related domain actions, including diplomacy?!? It's every guildmaster's wet dream, yet it's exclusive to Brechts and Khinasi, giving them a powerful advantage. Sorry to all you Brecht-lovers out there, but all this really encourages (in my own game) are Brecht and Khinasi merchants setting up shop in Anuire because the competition is "soft."

I would propose to drop the domain action bonuses, and instead expand the skill bonuses to include +2 to Appraise, Profession: Merchant, and Diplomacy[Bargaining]. It's already better than most feats right there, and if you use skill bonuses to calculate domain-level synergy bonuses, well worth taking. But the skills are very specific to merchants, hence the reason I'd allow 3 rather than 2 skill bonuses (comparing to other skill-enhancing 3.5 feats).

Master Diplomat: Same goes here. Drop the domain bonus (take Regent Focus for that advantage), but expand the feat to grant a +2 synergy bonus to Diplomacy and Sense Motive.

Finally, a note on establishing prerequisites: It seems a little ridiculous to have 1st level characters with feats like Master Administrator or Master Merchant. The current prerequisites are based only on attributes and race, but not at all on experience. Giving them a name with "Master" implies skill mastery and specialization. So here are a few suggestions for revised prerequisites, scaled for racial preference without making them exclusive (I think anyone can learn these kinds of specialties with time and experience, but cultures that expound these values give their people an early advantage). Note that elven and dwarven racial feats should (IMO) remain exclusive racial feats, as should the regional training feats. These are much more distinctive for each race, especially the non-human "secrets."

Master Administrator:
Int 13+
Anuireans, Khinasi: 5+ Ranks in Administrate
Others: 8+ ranks in Administrate

Master Merchant:
Int 13+, Cha 13+
Brecht, Khinasi: 5+ ranks in Profession: Merchant
Others: 8+ ranks in Prof: Merchant

Master Diplomat
Cha 13+
An, Br, Kh: 5+ Ranks in Diplomacy
Others: 8+ ranks in Diplomacy

Military Genuius
Int 13+
An, Vos: 5+ ranks in Warcraft
Others: 8+ ranks in Warcraft

Great Leader
Cha 13+
An: 5+ ranks in Lead
Others: 8+ ranks in Lead

Spymaster:
Cha 13+, Int 13+
5+ ranks in Gather Information

Conqueror:
An, Vos
-The character must have conquered at least 1 province through military force.

Regent Focus:
5+ Ranks in the key skill for the focus (Administrate, Diplomacy, etc.), and
The character must have successfully performed the chosen domain action at least 3 times as a regent or lieutenant.

How about adding Elite Regional Rogue Training (giving +2 instead of +1 to the listed skills; Prereq: Regional Rogue Training)?

That's all on that note, folks.

-Osprey