1. Western Style Food
I don't think you'll have a problem in either park. Although personally, I find the western style food (e.g. burgers and fries) to be less appetising than the other food available in the parks.
2. Staying at Disney Hotels
I would love to do this, but it outside of my budget (except for the value resorts at WDW). I'm not sure whether it is "worth it". I think both parks offer early entry for Disney hotel guests and the fact that you don't have to travel to the park by public transport each day is obviously a bonus (potentially a BIG bonus as travel times to / from Tokyo Disney sometimes took us up to an hour).
I guess it depends upon how much you value staying on site.
3. Number of rides at Tokyo
Disneyland and DisneySea
That will depend what month you go and what day you go. With proper planning and the dedicated use of Fast Passes, I don't see why you couldn't do 15 to 20 rides at Disneyland. Probably less at DisneySea simply because there are less rides (or at least there seems to be less rides, potentially because I ignore most of the kids rides in The Little Mermaid area).
It will really depend upon crowds, ride closures (whether due to maintenance or weather) and what rides you're interested in.
On my "worst" day at Tokyo (split between Disneyland and DisneySea), I think we only went on ... maybe three or four rides with only one ride at DisneySea (Tower of Terror with a three hour standby time). But, that was due to the fact that we'd already spent a full day at each park, the Fast Passes at DisneySea were all gone by the time we arrived around midday, Journey was closed which put more pressure on the other rides and after spending so much time in line for ToT, couldn't really tolerate any other long waits.
4. Culture Shock
I'm not sure about this one. I think it depends upon your expectations.
For example, I've been to Tokyo Disney with INSANE crowds. I was also at Disneyland LA in May 2016 and it was CROWDED. But, I much preferred the atmosphere of Tokyo Disney's crowds as they were orderly and polite. The crowds at Disneyland LA were disorganised and rude.
If anything, the US parks are probably more of a "culture shock" for me than the other parks. I guess Tokyo Disney is a "culture shock", but it's a positive one because I can't get over how polite and friendly everyone is and how ... dedicated everyone appears to be to enjoying themselves and sharing the fun with others.
In terms of language, bathroom facilities, food, etc I don't think there is any real culture shock. Just understand that you're in another country and that it may take one or two attempts to communicate something, but remain friendly and open and I'm sure you'll get there in the end.
I can't think of any local customs in Tokyo or HK which would be "shocking" in a negative manner. HK Disney may attract guests from mainland China, but with Shanghai Disney now open, I presume most of them would go there.