First time purchaser. Have a few questions.

First off I have done a lot of reading and research on everything to do with this process so I promise I'm not just being lazy and coming here to you guys for all the answers. But I do have a few things I want to clarify.

Am I completely fucked if I have to use my home address? (I don't really have another place to send it to)

What is the cutoff for a safe amount of powder H to order at once? Does it even matter?

Do I tell the vendor to make sure not to require signature confirmation when they ship or should they know already? (I don't want to insult anyone's intelligence)

Would it draw more attention to the package if I order express/expedited shipping or does that not matter?

Any other tips for a first timer that aren't covered in any of the guides or FAQs would be appreciated. Thanks everyone.