h1 approved for one year and stamped - questions

[mkds_29]

Hi, my H1B transfer was approved for one year, till September 01, 2013. I already got it stamped.

1. If I need to go to India to get married (possibly May), is there a time before when I need to be back in US? i.e will there be questions at Port of Entry regarding the pending duration of my visa?

2. Is there a time before when the dependent visa needs to be stamped since my visa is expiring in September? Will there be any issues for H4 approval?

3. If I get the visa renewed, with the same employer, is it true that there's an option to send to drop box for next stamping?

Please let me know. Thank you.