Thank you so much for steemworld. It's so awesome. If you want to estimate the RC costs of a transaction, like @aiyumi recommended, check out this part of beem. That's a submodule of beem, the leading python module for steem interactions, where all the RC costs get calculated. That could be of great help because you won't have to figure the exact calculation out for yourself from the steem source code.
Also, maybe you can get in contact with a whale on steem that would be ready to make his RC available for you for testing the account creation. I'd bet one of the bigger voters on your post would test that feature for you :)
Greetings,
Schwein