To beat Borg Cubes, get a capital class vessel, two plasma turrets and a cloak. Then, move to mid/long range and start unloading on the cubes, stay as far back as you can to avoid damage. When damaged, cloak and use the planet to repair your ship.
Clearly the Frigate is the defensive king, reaching 120 range. The Cruiser is the most economical of all ships, with a 220:160 cost to damage ratio with the 3rd upgrade star.
My favorite way to avoid armor depreciation is to collect four sets of Runed Reflective light armor. Reflective (45%) bonus maxes out in early levels, so does the Runed (+4) bonus. The major advantage to these sets comes from being able to return more than double damage when attacked, speed, and the mana needed to spam specials every turn.
A good way of making money is fighting the $1000 arena match as everyone knows, but, i've noticed that you can repeatedly Rogue special:steal on Team Ultima for big money ($400, $750). Tip: stay invisible, use magic potions, they more than pay for themselves.
After playing all the classes, Mages with +150 wands do the most damage by far (x5 attack for 30mana). Warriors with +200 sabers (x3 combo for 10mana) are second strongest. The Rogue and Warlock specials don't compare, they both cost more and do less damage ftl.
I've noticed that pets seem to avoid attacking during normal strikes, you're lucky to get one pet-attack in ten, but they'll pet-attack every other time when you're using special strikes. (Why?)
Lethal's blade "Jagged Edge" fails to upgrade, levels up, etc, I've found 4 orbs and it still says +50 dmg. After testing it, the only bonus damage after selecting an orb comes from the bonus +strength from lethal's armor.
I hate that soldiers will throw grenades from the bottom of the screen at targets they'd need twice the range to hit, isn't there some way of giving them a grenade range finder so our troops aren't constantly throwing grenades guaranteed to miss instead of firing their rifles...