1) No, it doesn't mean not bonded. Bonded thread has a coating on it to let it run through the sewing machine better, it doesn't make the thread stronger.
Here is the definition of non wicking thread from the Thread Exchange:
"This thread has a finish that resists liquids flowing through seams. There is a trade-off--some non-wicking finishes weaken abrasion resistance. You can minimize this problem by only using this thread when you sew high tension seams."
2) No, that is absolutely wrong, you should always use the same size top and bobbin thread. While the machine will sew just fine with different size threads, if one is larger than the other, the larger thread can actually cut the thinner thread.
3) No. I would put the feed dog with the larger hole on and leave it on. Your machine should be able to use up to size 24 needles, and the largest thread that will comfortably go through the machine is probably 207, and that won't work that well. I don't think 277 will work at all, but I don't know for sure. You can try if you like.
No one lives forever, the trick is creating something that will.