I make this suggestion because TAR will be very difficult to balance, yet it is a great idea and adds a lot of fun to the eco spot. It pretty much says, do you want to go trade, or do you want craploads of planets with tactical superiority?  I love having these sort of important choices, and would be sad to see TAR go and/or be marginalized to a heavy degree.

Edit: I guess I could say in a few words, with my idea i'm trying to simulate the initial outbreak of the rebellion, so that the player feels like they are participating from day 1 of the event.  Imo, this is a bit more exciting and lends itself to the style of gameplay we already have in sins, while not taking away from the whole.

Check out response # 50 for some good ideas on implementation while retaining unique characteristics.

So here is my suggestion:

Expand the idea of TAR by adding it to the repertoire of all rebel economy players.  Giving all rebel economy players this choice would give an eco player many more fun choices.  This would help to balance eco spots out, and give an even mix of any races loyalists/rebels a 50/50 chance to get in the eco spot in a large multiplayer game.

Give all rebel factions a Truce Among Rogues like capability with tec research at tech level 3, advent research at tech level 4, Vasari tech at level 4.  There would be no prerequisite diplomacy research for the rebel TEC, so they would be the most capable of early expansion to retain their unique identity as being very pirate friendly.

Edit: per my discussion with seleucia, this is a variable balance based upon what would be tested, perhaps tech level 4 is the perfect place for TAR, as it currently is in build .62

Give all loyalist factions a "cheaper planetary bombing ship research" that lowers per siege frigate cost in credits/metal/crystal/logistics at a tech level similar to the TAR tech level.

So at military tech level 4 for TEC, military tech level 3 for vasari/advent, all loyalist factions will have a researchable tech that will allow them to reduce the cost of their siege frigates after they have researched the siege frigate tech itself.  This reduction would mainly be to reduce the logistics cost of siege frigates.  I can't foresee this imbalancing the game, as siege frigates are pretty much countered by EVERYTHING in the game, and the tech for this research is comparable to the tech it would take to research TAR.  If planet bomber spam becomes a problem, you could always add an early research that would reduce planetary bombing damage by a % for all races, or add another planetary health upgrade for all planets/asteroids.

The thing is that the rebels going full on in TAR mode will be reinvesting all their cash in their planets, to a certain point.  The initial clash with your opponent needs to favor the loyalists in this situation, so that true territorial lines can be redrawn.  Rebels traditionally try to buy time, and loyalists try to exterminate rebels as quickly as possible to prevent them from becoming widespread...

Story wise this would simulate the surprise of a rebellion and the redefining of territorial lines.  Also there is nothing in game that really makes rebels feel unified under the title of "rebel"...traditionally rebels will ally with anyone to help their cause!  Since rebellions are usually started by a "smaller then the majority"(yes i'm deliberately avoiding an culturally charged word)  group of individuals, it would be safe to say that the rebels are fighting an uphill battle once they have made themselves known.  This would simulate the "surprise" of rebels occurring, and their quick acquisition of territory, and the loyalist response to this new aggressive faction.  Somewhere in the middle, depending upon player skill, the new territory will be fought over vehemently.

Let the planet smash/culture war begin!

This will be very fun indeed, don't nerf, BUFF!!! TAR is a great, big idea that would add a LOT more to the game if implemented in this fashion.

This will be easier to balance, as TAR will force developers to rework it constantly and since it is only one ability from one race, they may remove it entirely because it will be a pain in the rear to do all that work for one ability.  All i'm doing in this suggestion is to balance the game as the developers have already balanced the game before in the research tree.