Why is my gift not tradable?

The DX:HR inv item? I don't recall DX:HR being region locked... no idea.

bought from a new Steam account, just wait or send it

Could be do do with various reasons like SteamGuard, or how long it has been since the first purchase. It can still be sent directly to an account by using the inventory.

Probably this.

You should be commended for the accuracy of your username :)

"We require Steam Guard to be enabled for 15 days to help protect your items and Steam Wallet funds from being misused by somebody who may have illicitly obtained your password. If you have not had Steam Guard enabled for 15 days, you will be unable to trade. Accounts that currently have Steam Guard disabled will be unable to trade.
If you reset your password, you will be restricted from trading for 5 days. If your account has not had any activity for more than 2 months, you will be restricted from trading for 30 days. We do this to help protect users who lose access to their email account. Note that this does not affect password changes, only password resets."