First, I want to say a bit about the schools in Tokyo.  There are about 4 ways to teach in Tokyo.  One is with a conversation school.  The four big schools are NOVA, Geos, Aeon, and Berlitz.  They are like chain restaurants with locations in various places around the city/country.  In these schools, you'd generally be teaching smaller classes, like 1 to 4 students, or a bit more if you teach kids. Some students come quite frequently, so you'll get to know them, and some come just once a month or so.  Classes are about 40 minutes to an hour long.

Another way to teach is with a public school.  I have heard of cases where teachers work directly with the school as far as salary, etc, but have never done this myself.  I have substitute taught (and been a guest teacher) a couple of times (and I was Santa Claus once, but that's a different story) at public schools.  There were about 40 or 50 students in the class, and I saw it as pretty chaotic and difficult environment to do very much but give a Conversation Of The Day, practice a couple times,  hand out and collect homework.  Classes are about 40 minutes long.

(I believe JET helps people get started teaching in public schools.  The few people I've met / known in JET say they really like it.  The trick is their long setup time, like 9 months.  So, 3 months into your first year, they ask if you're ready to sign up for year number 2.)

A third way to teach is to find your own students and meet in cafes.  http://findateacher.net/ is the most popular way I know to get started in this.  The good thing about this is you totally control your own schedule and your own price.  But the hard thing is balancing numbers of students / free time.. I would have students for a while, then they would quit for some reason or another.  And then it was hard to find another student to fill in that timeslot.  Also, a problem is I'm lazy and don't want to make a big effort to find students and work.

A fourth way is with a company that sends teachers to businesses, and classes are taught to groups of co-workers all in the same company.  I know a guy who's doing this, but I don't know any details.

Okay.

I have done options 1 and 3 above (conversation schools and findateacher.net).

I came over with NOVA and worked for 1 year. http://teachinjapan.com/ The good thing about NOVA (and there are very few good things about NOVA) is you can quit easily once you get here and they won't be phased by it.  The average duration of a NOVA teacher is like 3 months, or something really short like that.  The school only cares about making wads of cash; they don't care about teaching the students.  However, some NOVA teachers do stay for a really really long time.  If one can submit to the rules of NOVA and not actually care about teaching, it's an easy squeezy braindead job.  I encourage you *not* to go with NOVA.

I have also worked for 1 year at a school called Gaba.  http://careers.gaba.co.jp/  I don't know if they hire people who are not currently in Japan, but you can contact them.  Gaba's good point (for me) is teaching 1-to-1 lessons.  I believe I can help more easily if I can talk to one person, figure out what they need to work on, and tailor a lesson exactly for them.   Gaba's other good point is also its bad point: numbers of students to teach per week is not guaranteed.  If we have a student, we get paid, if there's no student scheduled, no pay.   Generally speaking, if you work during the busy times (nights and weekends), then you will have plenty of students and make enough money.  And as students get to know you (and like you), they will choose your lessons.   Schedules are made a month in advance, so I can schedule time off for myself next month, just by telling the school manager.

I have also worked for a year with English Village.  http://english-village.net/  This school is similar to Gaba in that the scheduling is done on an ongoing basis.  In the same way, pay is not guaranteed, but if you work in the busy times, you'll have plenty of students at it will be fine.  I know teachers who have worked for *years* at English Village.  Like 4 years, 5 years, 8 years, 10 years.  I recommend English Village if you want to work at a conversation school in Tokyo.  (I don't know if they will take teachers with no experience, though)

I've been based in Tokyo for four years now.  I've taught solidly for 3 years, and spent 1 year semi-teaching and traveling (very long story involving a cruise ship).  I've gotten a good start on year five, now, and will be doing IT work instead of just teaching.  Maybe some of both. 

In the conversation schools, about 8 or 10 classes, 40 minutes each, with a few breaks sprinkled in.  Schedule details depend on the school.

 

Yes yes.  It will likely cost about US$2000 to US$3000 to get started in the first couple of months in Japan, but after that point, you should be in a positive cash flow from your job.
 

yes 

yes

no

There are enough English speakers in Tokyo that there are some magazines that cater to that population, but it's still semi-rare for me to see a foreigner here.  I almost always acknowledge foreigners with a nod/smile or even talking to them when I see one.

Um, yes, but there is some racism.  For example, Japanese people would generally rather sit next to another Japanese instead of next to me.  I don't see this every day, but it's often enough that I notice.

There are demonstrations, but they are peaceful and hypocritical.  Generally speaking they are just a guy yelling through a microphone about how Japan should be kept pure.  But generally he is ignored by everyone but a tiny crowd around him.  I've heard of cases where the guy will have McDonald's for lunch and then be back on the microphone yelling about the greatness of Japan.  I've also heard they are complaining more about non-Japanese Asians than Westerners...   Except that they are loud and annoying, these are easily ignored.
 

Yeah; don't worry about them. 

Definitely not.