Wow.. If I had a Macbook Pro I use for my job with $4000+ worth of software I can't redownload, AND in the middle of a financial struggle, I would be guarding that Macbook with my life...
And if you really do have a legit job in video editing, wouldn't all that software be provided by your employer?
But anyways, I don't think Apple is going to replace your logicboard for free, since the logicboard is basically all of the core(ie. expensive) internal components of the Macbook soldered together :/
Your best bet would be to look for a similar Macbook that's functional, but with like a broken screen or something. Then you can use that logicboard on your Mac.
Or you could try finding a cheap place to buy a logicboard by itself.
Or if your screen is still functional, you could try selling your MBP and describe as "Fried Logicboard, but LCD still intact". There must be someone out there with a cracked MBP screen who doesn't want to pay apple $600 to replace it, and would rather just buy your fried MBP and salvage the screen. You could then put the money towards a new mac.