Note: Warp weapons can be quite handy on a support ship.
Since they teleport the ship to a random location
on the combat map, they are usually more effective than repulsor beams would be. Most of the time, the enemy will end up 3-4 turns away from combat, and you'll improve your odds locally.
If you manage to hit the fleet leader, or just provide a good volume of fire, you'll be able to massively disrupt the enemy formation. Fighting a handful of ships at a time is much better than fighting the whole fleet
There is always the risk that it will be moved behind your lines or beside your retreating support ships, so consider your fleet composition when deciding to use them.
---
3) Don't look to the descriptions, they're more atmosphere than details.
Look at the stats listed on that page, particularily the abilities at the bottom.
Ship hulls also show their abilities in the small window below the hull selection box in the design screen, and you can click the abilities tab of any ships you've constructed to see a handy list.