For fiest error, you need internet connection to download eclipse java version. If you already have the eclipse version then you can put in the lib folder so the build does not download it. The name of the eclipse zip should be same as reqhich uired by build which you can see in the command console.
For second error you eneed to check if there are other errors on the console as it works without problem for default setup.
I just tried for one of the developer for our use and it worked perfectly fine for JBPM 5.4
The OS of the machine does not matter but I also used Win7 64 bit machine.
I know I need an internet connection!
Anyhow, the issue was resolved and if it works differently in different systems, I hope the "edit" helps you check it out.
Thanks and regards,