Let me add some perspective as an expat (Australian) living in NYC.
1. You may not be a native English speaker but honestly your English (based on your writing here) is fine. Assuming your conversational (rather than written) English is at a similar level, it should be a non-issue.
As to whether it will hurt you in terms of your organization and negotiating renumeration, that I can't say. It depends on your employer.
2. As for your salary expectations, different companies have different structures/mixes with regards to base salary, bonus, stock and other benefits. Your salary range doesn't seem unreasonable however.
3. Where to live. OK, this one is a lot more complicated and largely comes down to what tradeoffs you're willing to make.
If you live in NJ you're basically looking for something along the PATH line that goes into Wall Street. The problem with PATH is it doesn't run after a certain hour and doesn't have great service on the weekends. I know people who live in NJ who drive into the city on weekends. This means living in NJ can mean a more isolated existence (socially/culturally) and/or owning a car, which is an expense that you don't really want (IMHO).
If you live in NYC you pay a city income tax, this is true, but IMHO it's the one tax I don't mind paying because you get a ton of services for that money: 24 hour subway, a responsive police force (eg it took the NYPD 15 minutes to show up on a Saturday night to disable an unattended car alarm outside my building), a fairly new (and seemingly popular) city bike program ($95/year).
Working on Wall Street makes living in Westchester or Long Island more difficult as those commuter lines generally go into Grand Central or Penn Station (respectively), which means you have the train ride and then a subway ride. That's a long commute.
Living uptown means a relatively long subway ride. Upper East Side means catching the 4/5/6, which is the worst and most crowded line. Queens is relatively inconvenient too.
So, if I were you and wanted to live in NYC I would look at downtown Brooklyn or somewhere around Chinatown. Get a small apartment, pay $2k+ for it but have the subway, have a shorter commute (you could walk from Chinatown) and be around more people.
4. I don't think 40% is accurate. The marginal rate might be that but it won't be 40% total. Living in NYC you pay the city income tax but the NY state income tax (which you also pay) is lower than the NJ state income tax IIRC.
5. I can't speak to the working conditions on Wall Street but my understanding is that Asian working hours are pretty high anyway so I wouldn't expect anything more than that.
6. Processing times for Green Cards come down to what category you're in and your country of _birth_. This is super-important. Hong Kong, I believe, is treated differently to mainland China (the latter having much longer processing times).
EB1 category is hard and unless you have a PhD, are published and cited and you've been in a position of judging other people's work in that regard, you won't meet the bar. Being a "senior developer" certainly isn't enough.
This leaves you in EB2, which is employer-sponsored. If that interests you, negotiate that as part of your relocation (that they begin that process straight away). Expect it to take at least a year or two.
But in all matters visa and immigration related, make sure you speak to a qualified immigration attorney rather than relying on any advice you get here or elsewhere.
Some additional things to consider:
- Living outside the city makes not having a car more awkward. Factor this in as an expense;
- Don't make a decision based on relatively small differences in income tax rates. There are far more important factors than this such as being happy where you live;
- When you move here, take a sublet and figure out where you want to live;
- As part of a relocation package, get your employer to pay a broker fee for finding an apartment and ideally give you 2+ months of corporate housing to find your feet. Broker fees on rentals are typically 15% (of the annual rent) in Manhattan and a month's rent outside of Manhattan;
- Even if you have to pay that fee yourself, it's well worth paying (IMHO). It'll save you a ton of time and if you get a good broker you won't waste your time with buildings you can't get into (no credit here will initially be a problem) and you should get something below market enough to justify the cost if you stay in it for 2+ years;
- Take a 2 year lease when you get an apartment instead of 1. It's easy to get rid of a reasonably priced apartment if you change your mind;
- Cathay Pacific has 4 direct flights a day from JFK to HKG (and they've just added one from Newark). I love Cathay and fly that route a lot;
- You might get an L1B but next year, as a backup, get an H1B. You never know how long a GC will take;
- You shouldn't need to take a sub-market salary to move here. Don't lowball yourself just to make sure you get here. If HR wants you to pick a number, go _high_. You can always come back and say you're somewhat guessing because you're not familiar with the market if you're way off. It's perfect actually.
Hope that helps.