I haven't tried it.

I have had a burning desire to make a mod that includes altering ship roles significantly.

Never made a mod before.  I intend to get to it after my most of my MTGO cards rotate out of the standard format mid-April.  (I intend to get the most fun I can out of my $800 dollar investment with Wizards of the Coast while I can; they'll never see another dime from me.)

The mod I envision has five parts:

1)  Reset targeting and defense priorities too more rationally represent my vision of the ships' battle roles, make the battle system less exploitable through role assignments, and bring starbases to the front so that they participate in the full engagement.

2)  Make some less significant alterations to the shiphulldefs.xml.

These ^^ I know how to do.  3-5 I do not know how to do and may not be possible in the .xmls.

3)  Restrict role assignments to particular hull sizes.  Aka, only tiny hulls could be assigned the interceptor role, escorts could be small or medium, and huge hulls could only be capital ships.

4)  Make the role assignment include modifiers to the ship's stats that included both bonuses and penalties to help the ship fit it's combat role.

5)  Allow shipyards to produce multiple ships per turn so that the smaller hull sizes can be integral to strategy throughout the game rather than obsolete by mid-game.  I saw Paul build 14 constructors in a single turn on the 3/24 stream, but I'm sure it was a console cheat to auto-complete everything in the build queue.  Still, it shows that the game will allow multiple ships to be launched from a shipyard in one turn- it's just blocked somewhere.

So Gauntlet03, if you can hold onto your curiosity for a few weeks, I'll get to it in it's time.

No way to do this *currently,  Paul has said he is thinking about it .. or was it frogboy?

I have been wrong before so grain of salt here

This is how the system already works.  Tinys are interceptors or Guardians.  Smalls are assault or escorts. Mediums are assault/capital or escorts. Large are capital or escorts.  Huge are capitals.  And everyone can be support.  The problem is they gave the player the ability to cheat the system, which I've grown to increasingly believe was a mistake.  Why restrict yourself to the system when you can get around it and smash the AI who is hobbled by it?

The system in essence does that.  Attackers are meant to have high damage.  Defenders high defence.  The cheating negates it for the player. 

I'm pretty sure he just used the "Finish" command, which builds everything in a shipyard's queue.

It starts a comment, so code inside the marks doesn't have any effect. It starts with <!-- and ends with -->.
Comments are used as an easy way to disable code without deleting it.

I don't really agree. Removing the player's ability to set the roles of ships regardless of what the computer thinks the role should be only fixes the most extreme abuses; it does not fix the underlying problem in the system. The underlying problem that the system has is that there are certain role pairings (Escort/Capital, Guardian/Support, Escort/Support, maybe one or two others that I'm forgetting) where ships of the first role are always attacked before ships of the second role, regardless of the roles used by the opponents. As long as that flaw exists, it will be possible to abuse the system by making glass cannons out of the second role and bricks out of the first role. Removing the player's ability to set the role of the ships just limits the player to best bricks and glass cannons that will fit into the roles as the computer assigns them rather than the best bricks and glass cannons that the player can make.

The loophole that we can abuse to create fleets of glass cannons with a tank or two to absorb fire could be shrunk simply by ensuring that there are no role pairs such that the first role in the pair is always prioritized ahead of another role in the pair (although such an arrangement still allows there to be fleets composed of tanks and glass cannons, such fleets can no longer get away with only a single tank or tank role; for example, by making Interceptors have a target prioritization of Guardian>Support>Capital>Escort>Interceptor>Assault and making no other changes, you've removed the Escort/Capital and Escort/Support pairings without introducing any new pairings, and a tank+glass cannon fleet which uses the Capital role for its glass cannons now needs to have tanks in the Guardian and Escort roles to ensure that the tanks will be attacked before the glass cannons by any arbitrary opposing force whereas at present you only need tanks in the Escort role; this weakens the tank-glass cannon fleet by doubling the number of tanks required for the fleet and imposing a corresponding reduction in the number of glass cannons which can be included in the fleet), or removed simply by ensuring that for every role there is at least one role which prioritizes it over any other role (which means that for any possible tank-glass cannon fleet composition, there is another fleet composition which can hammer the glass cannons without needing to go through the tanks, significantly increasing the risk involved in making use of glass cannons in the fleet).

I've redone BattleBehaviorDefs.xml and ShipHullStatDefs.xml.

In the process I've broken some ship blueprints and need to go through every drone spawning component, module, etc. and do some cleanup.

I need help.

First, what's a good program to use?  I was using notepad.  When I saved as a .xml it was saved as a Word document.  I don't have Word and they're not getting $60 from me.

Second, is there any text for defense components besides "BestDefense", soch as "ShieldComponent" that the schema will read?

Here's a dropbox link for what I have done that will probably not work.  The files aren't in .xml and probably need converted and or renamed to function.

EDIT: deleted useless links.  New link to first version of mod below.

Thank You.  I have Notepad++ now and it's a breeze.  Looks like I have to redo my edits.  The files are encoded.  I hate Microsoft.  Tried to get Notepad 2.0 last night to see if it would let me work on the files.  They tried to bribe me with free music for a 5 star rating.  Gave them a No Star rating and didn't buy the program.