1. How do i get the Engine if i purchase?
You are emailed a direct link to download it from your REALMCRAFTER account.
2. Can i purchase by Credit card or paypal?
Yes
3. I would like to known if Realm Crafter Engine can make a Game Similar to Runescape.. Map Terrain,Npc,Quest(reward),Teleport,Level,Skill,Money,Non membership features and membership.etc
Without you editing the source No, it can do Terrain, maps, npc, quests, teleport, levels, skills, money but non membership and membership would either use the source or using lots of scripting and a MySQL Database.
4. So does the player just create a account in my server and then they can play?
They have to download the client, then just make a account create a character and play yes.
5. How can i let my friend or release to the public?
You hit Build game, then send them the client files. you obviously need a server to host the server files though.
6. I wonder is it work if i make a Official Website and Let them See my Server Status,Register,Download my Game ( What do i need to give them in order for them to play? )
If you program the MYSQL and the website to allow this then yes. www.apoc-online.net do this and they used RC to make the game
Hope that helped

Just ask for any more info
My MMORPG: check out the forums at http://www.mechtec.net/forum