IMO, a good warship name should be one of honour, prestige, describe the fighting style of the crew or hint towards the ship's history
But based on the given descriptions, here's what I got off the top of my head (I like latin names)
Bomber- Periculo. Meaning "Dangerous" both for enemy and crew
Heavy Cruiser Warship - Tempesta. Means "Storm". Mobile but packs a punch. Can provide good sustained damage, much like a storm
Dreadnought - Praesidio. Means "Protect", ideal for a large warship that can take hits on behalf of the weak
Alien Ship - Novis, meaning "Strange or Stranger", fits because its an alien ship and not like any of the other human ships
Powerful bomber - Praecept, short for "Praeceptorum" meaning commander. Fits because this ships would be so imposing as to command respect and (I would guess) as a flagship of the federation fleet