hiya. I've been following this game for about 6-7 months now. I will answer from my knowledge, so it may not be entirely accurate.
i) So, I believe that it was meant to be released this month (March) on the 24th (yesterday) but it has been pushed to next month. The game is going to be released in stages. We are going to be getting the town square module. This will be released in April.
ii) The game will have players. It is estimated to posses around 300 per server.
iii) You can work in game as whatever you want. It's like Rule 34; if it exists, it can happen. you will be able to buy houses, however, on the server you decide to play on, if you buy the house, that will be yours and no-one else can buy it. Don't worry because there are plenty of servers to choose from.
Hope I have helped. Refer to the link below for more useful and interesting Info.
http://www.identityrpg.com/info/faq/
Sincerely,
Mr. Stafkauser