1) If you pay tax on the pension, you can not claim any treaty benefits, so your treaty question is moot.
2) Technically, all wages, including your employer's matching contributions and your contributions, go on line 7. All go on Form 1116. All EXCEPT matching employer's contributions go on 2555.
3) In practice, you may have to enter the employer pension contributions on a separate line (line 21), as most tax programmes do not have the facility to notate an item being allowed for 1116 but not for 2555.