Reading a few of the Dev threads I fleshed out an idea on how to do a career centric quest set which ties everything in and lets all players get the same reward. I'm using Federation titles and terms but I'm pretty sure this would work for Klingon side as well. Observe:
The player, one he reaches a certain rank is hailed by Starfleet's Admiralty with a message that Intelligence shows the Borg are gearing up for yet another push into UFP territory. Since they have been continually adapting to everything we have it is time to come up with something new. Your assignment is determined by your career path:
Science Captains must go explore planets in some of the outer lying territories and study lost civilizations for untapped concepts and technologies.
Engineering Captains must report to one of the major stations to lead a research team to design a device based off data gathered by the Science Captain.
Tactical Captains must lab test these devices first in a holodeck run and help work out the bugs.
These missions can be run separately and the player can assume that NPC's other than his character have or will fulfill the other missions.
The thing is a dud and no one has any solid reason why. It should work but it won't. These missions could be given as a player hits their next rank or immediately after the previous missions.
Science Captains must study the device at a space station and run through several logic puzzles to try and devise theories behind why the device fails.
Engineering Captains must take the blueprints to Memory Alpha and research with the NPC's there information on furthering the design. This could include having to deal with the Ferengi there who will not give up their knowledge without payment.
Tactical Captains must take the device to a barren planet for further field testing against holographic opponents...but the Klingons or another alliance are laying in wait to kill them and take the device to include in their own researches for their own anti-Borg arsenal. In facing off against them more details come from how to try to get the device to work taken straight from data in the tricorders on the bodies of your opponents as well as finding their own version of the device in the wreckage of their starships.
It works...we hope...maybe...time for more testing.
Captains will take the device to a system devoid of life for deployment and remote testing in their ship's labs....when the Borg show up. Somehow the Borg have arrived in system and beamed aboard the vessel before detection. It's a fight through the decks of the ship to clear the ship of the invaders...and plenty of chances to check and tweak the device until finally, it starts to work. Not 100% of the time but it does seem to affect the Borg in random ways. Some shut down, some find their minds freed of control and act out randomly, some transport away, some explode causing AOE damage.
After handing in the battered but field tested device and all the data gained from the surprise attack the teams at Sol Station and Memory Alpha have it figured out and have replicated a set of the devices for field use. They need to be deployed quickly because the Borg already have experience with the thing's effects and will be working on ways to adapt to it.
This mission is a team mission and needs at least one player Captain of each career path. An isolated Bog Cube has been discovered and set upon by a large NPC Fleet. The players will join the assault and, once the cube is disabled, beam over and attempt to install the main device in the Central Control Node of the Cube. Each Captain will have his own tasks to perform during the mission. Once done they must activate it, beam off and flee to a safe distance as the Cube comes back to life. The device begins to interface with the Cube and...well...I don't want to spoil it for everyone so let's just see if the Devs and Cryptic Writers like the idea.
I'd be happy to work with them over fleshing this out and making it work.
There would be mission rewards, of course, I'm thinking the final reward would be a Liberated Borg Phaser Rifle with a secondary attack tailored to the character's career path: science would be a stun expose, engineering would be an expose debuff and tactical would be a nanite exploit where the nanites eat away hitpoints.