Sorry, but a arrestee cannot be compelled to consult with counsul.
Not "compelled" but have a continuing right to, under treaty.
If the right is continuing, yes there is. There is also a requirement that the representative of the foreign government be informed.
Again, in all case in Mexico v. US are
death penalty cases, so I'm not clear that this applies to all arrests or all felony arrest.. As noted, in cases where the death penalty was commuted, the claims by Mexico were withdrawn. Why don't you link to the actual treaty.