instruction:
Given a travel related situation, and given a specific question about the situation, summarize the question into a title
question:
My problem: I recently booked a business trip about three months out, noticing slightly too late that there's a huge event (Formula 1 race) happening in town the previous weekend and all the remotely convenient and/or comfortable hotels are asking crazy rates (US$500+).

The usual rule of thumb of booking flights and hotels is the earlier the better, since prices usually go up but rarely come down.  In this case, though, I have a sneaky suspicion that hotels may be demanding too much and there may be a fire sale of unsold inventory right before the event.

So: Do hotel prices generally go down right before big events? Bonus points for answers with data instead of just speculation.

(Note: this question has been edited, as I'm more interested in the general question above than the specifics of my situation.)

Interim answer 1: I've followed simbabque's answer and booked a mildly inconvenient and mildly crappy but fully cancellable and not crazy expensive hotel to cover my ass, and will check & report back on the hotel situation before arrival.

Interim answer 2: Idly poking around, I noticed that a big chain hotel near the office that had previously been 100% full had a room free for all three nights at our normal corporate rate (~US$120).  Booked!  But I'll still check before arrival and report back for science.

Very overdue final update: I didn't do a very thorough check because work, but a casual browse on Google Hotels did show a bunch of hotels offering rooms at less stratospheric prices (under $300). YMMV.

answer:
When should I book my hotel if prices are inflated due to a major event?


question:
I booked a flight a few months ago using an online booking agent (cheaptickets) from Zhangjiajie (China) to Chiang Mai (Thailand). The flight details were as followed: 

9h50 Zhangjiajie - 11h25 Guangzhou
A stop for 4h35
16h00 Guangzhou - 17h50 Chiang Mai 

Yesterday the booking agent mailed me stating that China Southern Airlines changed their flights and asked me to send them an agreement for the proposed changes. The new changes are: 

19h50 Zhangjiajie - 21h30 Guangzhou
A stop for 11h10 (so +1 day)
8h40 Guangzhou - 10h25 Chiang Mai 

This is clearly a disadvantage for me, because I don't want less time in Chiang Mai and I don't want more time in Zhangjiajie. So I replied and said that I didn't agree with the changes and I just got a response stating that this is my best option. 


Am I allowed to ask for some sort of compensation, because of this? Although it's probably the China Southern Airlines' responsibility. 
Or could I ask them to put me on a flight earlier which has a stop in Guangzhou for 18 hours, so I can at least explore the city a bit? 
Are there other options or factors I should keep in mind or that I can do? 


Note: My other flight from Brussels to Beijing with Hainan Airlines (using the same booking agent) also changed 2 days ago, but the changes were not that drastic. 

Edit: I ended up getting a flight a day earlier (which I mailed them for) so I had 18 hours in Guangzhou so I can explore it a little bit. They had to check this first with the airlines and it was approved. Since it was a change of the airlines (which they can apparently make any time) I didn't get a compensation or something. 

answer:
My flight is changed to include an overnight layover, can I claim compensation from airline?


question:
I am a European citizen with Spanish passport and therefore I needed no visa for tourism in Japan. I was given a 90 day period (Sep 16 to max. Dec 15) and within that period I must go to the US for an interview (Nov 30 to Dec 5) 

My flight back home to Spain is on Dec 14 so it is not an extension of my original period what I am after. 
I just need to interrupt my holiday for this specific thing and I am afraid of not being able to re-enter, join my (also Spanish) wife again and finish our vacation normally.

Is there any objective information about the regulations regarding re-entry for this type of permit?

answer:

Re-entry to Japan within 90 days period as a tourist?