First of all, there is a website you can go to that will tell you FP+ availability for high-demand attractions. I think it'll only show availability if a large group of FP+ open up, due to added hours or other changes, as opposed to small groups of people canceling or changing their reservations, so it may not be exactly what you want, but you can try it anyway. I don't have enough posts to be able to post links, but try searching for "latest fastpass+ availability" at a site called theDIBB. Or maybe someone else who knows what I'm talking about can post it in this thread.
I cannot answer your actual question about the viability of stalking
MDE, etc. (and it seems like you got them so you don't need more advice anyway!) but I can help explain why drea21 was able to get FP+ for the parades.
I am also going to MK on Jan 18, and (probably because it's the first day of my trip) I was unable to get FP+ for MSEP at the 60-day mark, but I randomly checked the website that I mentioned above and it showed availability, and sure enough I was able to get 5 FP+ for MSEP at the 29-day mark! I had originally heard that FP+ for parades and fireworks opened up at the 30-day mark, but in general I don't think that's the case anymore, because at my 60-day mark it showed that all FP+ were taken for the parades and fireworks on Jan 18, but they were available later in my visit (on days I'm not planning to be at MK). However, it did seem like they had opened up a new group of FP+ at the 30-day mark.
I was confused by this so I searched around disboards to try to figure out what happened, and what seems to have happened is that they opened a new area for FP+ viewing, in Town Square (at the flagpole near the entrance). If I understood correctly, Disney opens this 2nd area on more crowded days, and this 2nd area in Town Square is not as nice as the Hub viewing area (but I assume still better than staking out a spot over an hour in advance). However, some people seemed to think that all MSEP FP+ viewing will be in town square, due to Hub construction, and more FP+ opened up just because it's a bigger area. I don't know which is accurate but it doesn't matter very much to me, as the Hub is unavailable to me now regardless and Town Square will be just fine.
Hope that's helpful!