Tier 2 General - Apply from USA - timeframe

Hi, I have a question. I am applying for a Tier 2 visa from the USA, so I'm filling out the online form, and then I will book my biometric appointment. In the instructions it says that then I have two weeks to post my application to New York.

Does that mean that the stamped date should be within two weeks, or that it should ARRIVE there within two weeks? This is important because I have travel arrangements in a couple of weeks, and I can make the appointment before traveling (I need my passport for this because it's abroad), but then I return 12 days later, so 2 days before the 14 day limit.

Also, can you confirm whether I need to hand fill any extra forms besides the online application form? Nothing appears here:

https://www.gov.uk/government/publicati ... in-the-usa

but reading around, many people also hand fill the Appendix 5 of the VAF9 form. Do I have to do it? I guess there's no harm in sending it as well..

Last question: what does it mean to "apply at the same time" when it comes to dependants? I have created my main application, and my wife's application separately (as a Tier 2 dependant), and of course some of the data is cross-referenced (passports, CoS), but each has its own option for biometric appointment, pay, etc. What do I have to do to have both applications considered to be 'at the same time'? Just sending them together to NY in the same envelope? I need this so that my CoS can certify maintenance for her!