here are your answers for your questions:
Will SP run on Windows 7 64-bit?
- the support of 64-bit systems is not official, but our application works with 32bit mode of browsers on 64bit systems.
Will it sync with my Android phone?
- not for now, but Android version is in our plans
Is the data file stored ONLY on my computer and not on any of your servers?
- yes, it is true. The data are stored only on your PC, they are not being sent or synchronized to anywhere
Can SP enter credit card details into online forms?
- yes, you can use Identities and fill all the types of online forms, including credit card details