My advice is, take a flyer and have some fun here.  Just do it with no financial goal and treat it as a learning vacation.  Re your specific points:
1) Don't think of it as business.  Just as a vacation/investment in future business.
2) Lots of girls tour here for the first time, and being "established" is really not a problem.  Advertise here and in Eros and CityVibe.  Your site and pictures are great and your prices are right for the market.  That's a forumula for success.  Your number of reviews are the bare minimum, so you might try to get a few more good ones before coming.
3) Don't be scared of LE here.  If you are savvy and reasonably careful, you'll be fine.  LE here is not looking to bust indie girls, only agencies.  You'd have to do something very indiscrete to get caught.
4) Best month? Personally, I'd say the spring or fall months are the best.  May, June, Sept. and Oct. The climate is usually wonderful then, so the experience of being out and about is the most fun.  Other providers will have to advise you on the business side of the timing.
5) I'll PM you with some of the good hotels I've gone to for incalls.
6) Personal safety.  NY is quite a safe city unless you are unwise enough to wander alone into a rough neighborhood.  None of the areas around where tourists go are unsafe and the same is true for areas around the good hotels and shopping.
7)  There's no way to guarantee how much you'll make the first time.  That's why you should consider it a vacation/investment in future business.
8) Marketing.  Try the Providers Only Board but my thoughts on where to advertise are above.
9) Being on your on in NY is fine.  People are actually very friendly, especially to beautiful women. Just do it!

1) Going to a city you've never been to before can be scary, and NYC can be intimidating.  2) If you are not established in the USA or New York, there are things you can do to get a toehold.  One thing is to attend a meet & greet cocktail party, and get to meet the players here.  Check the M&G board...there is one upcoming.  3)  Screening carefully will mostly alleviate LE.  4) Best time to visit NYC is in the spring and early summer.  Hotel rates are lower, and the weather is usually good.  5) There are many excellent hotels in NYC.  Just post on the NYC board that you are looking for advice on that.  6)  Manhattan is safer today than at any point probably since the American Revolution.  It is unlikely that any place you rent will be broken into, and if you are careful with screening, your chances of encountering bad hobbyists are relatively small.  7)  NYC is expensive, no way to sugar coat it.  8) Post on the NYC board that you are interested in touring NYC: some of the ladies here will be willing to give you advice.  9)  Being in NYC alone without a support network...this is indeed intimidating.  My best suggestions would be to travel here as a tourist first, and a provider second.  Be selective and cautious in the latter pursuit, but don't be afraid to travel here and see the sights...there are so many worth seeing.  New York is one of the special places on Planet Earth, a place you do indeed want to visit.  

BTW, I checked out your website.  Most impressive, and all reviews are 8 and above in both categories.  I would think you could indeed establish yourself here, as other ladies from the UK have done.  Hope you decide to make the journey...

Regards,  

CD