It can be done rather easily as Scoutdog mentioned -- via a mod folder.
While extensive editing of the TechTree & ShipComponents xmls is a matter of finding the proper values & data for whatever you have in mind, there is a simple concern that must be taken care of first; Defense to counter react to these "new" weapons.
Balancing is important for another (less obvious, probably) reason... AIs algorithm.
Lemme give you a simple example from the currently developping X-Worlds mod;
- Tiny Hulls have been resized to 20 instead of 16; what do you think the AIs do with that small space? more Support and as a result -- huge range for their early scouts! All ships were raised a notch, except for the Huge which got dropped at 128 -- again, for late gameplay balancing & to limit behemots of 10+ maxed Eruptors, etc.
- The TA Atlas system of defenses is also ported back to DA, indirectly... yet, the extra strenghts were inserted in a specific area of the techtree so that their **INCREDIBLY** strong advantages aren't interrupting the main 'most powerful race' ratio calculations that the engine develops as a diplomacy_war trigger condition for AIs... but, at the same time puts everyone on a sort_of quiet mode for awhile UNTIL very late in the game when there is only but one way to cut through these high defenses; miniaturization and specializing your attacks. Fine-tuning, but battles become a wrecking hellofatreck between repairing & timely shots at the right fleet at the right moment with the right BMDs hitting the proper Shieldings or not, etc.
- The introduction of "Spy ships" with absolutely weird speeds and a few key modules & components was also a huge gamble with how AIs would react... after a few tests, it looks like they took the bait and it makes for interesting situations; mind you these specific ships are pre-built, no hardpoints left for them to add anything and are strictly driven by two process; inspect the map & invade with low numbers to sabotage enemy's buildings only. That's the intention, as to code this all in i can only hope some devs will "agree" on the principles.
Sooooo, conclusion?
Anything can be done if you know or can guess the exact consequences of all modifications introduced by a different set of weapons -- or by any other means; just the 37 XW-Trade Goods are proof enough.
