Tiny Tim
Still Mildly Glowing
It's implied they are looking for FEV (no green stuff here...) so big important looking buildings to borderline retarded super mutants looks like a place you could find important stuff.
As for the Talon company I believe you can find a note saying they are being paid by an anonymous customer to clear the capital building out. Though Bethesda never goes into who's paying the Talon company to do any of things they are doing. Or the fact that the Capital Wasteland is practically devoid of any civilization, and the only people who are rich in the game are rich for no reason.
This pissed me off when i first played the game years ago as a good guy . I felt the game was pulling a scam on me , starting a story with no desire to complete it just to mess with the player .
I saved megaton and killed mr.badguy there , and soon after hitmen came after me carrying a note with my name . I was kind of thrilled . I thought it was a consequence for my actions , that i ruined the plan of some evil faction who wanted to nuke megaton for some good reason , possibly connected to the enclave which was then on the radio.
Then came the regular attacks by Talon Company , who said that they were payed by someone to kill me for being too nice . I thought it was a metaphor at the time , i didn't think the game was just that stupid! I remember wondering who is paying them and travelling the wasteland looking for bits and pieces to find out .
Afterwards , when i discovered tempenny tower , dukov , the talon company headquarters and the backstory of "you gotta shoot them in the head " quest , i thought i was discovering parts of that very evil faction , and wondered what their plans where and what they were paying talon company ( a whole army of them ) to do .
Even when i finished the game , i couldn't bring myself to admit that it was all just fucking random , so i assumed that as an evil character you would able to work for tempenny after blowing up megaton ( who, by the way, i assumed had a reason for wanting to blow up a whole city ), that you'd find out his plans and that the talon company mercs would be friendly then .
But no , the talon company is just like the supermutants , the enclave , the raiders, the molerats and everything else in this game , spawning in random places and killing stuff for no apparent reason .