I count 4 questions.
Using content from SH4 will not happen. It's perfectly acceptable, if you own both SH3 & SH4, to use pieces in each game on your own PC but SH4 content can not be distributed as part of a free package for SH3.
That is not to say that you can't use ideas from SH4 and tailor them for SH3 but there will never be SH4 files copied directly over to SH3/GWX.
I don't know if this is a legal issue or not. I know that as I'm not an owner of SH4, I should not be in possesion of any SH4 file, however they came to me.
Time Scale - the GWX team has set it's own deadlines purely for developmental reasons. Not having a deadline means things can 'drag on' indefinately. However, I'm sure that when the time is right a statement will come from the team. In the past the dev team has stated that only when the files are stable and fully tested will a release be issued.
The remaining questions - I believe Kpt has commented about content that might or might not be included and that it will remain a closely guarded secret.
For now Kaleuns, continue to sink those ships.