Kevod Harav can someone sign off on a car that was already agreed upon 3 months ago on chol hamoed (he has no other car)?

Can I sign a lease for an apartment on chol hamoed if there is a great chance that it will not be available if I wait until after Chag?

I am having a packaged delivered on shabbat by USPS that requires a signature. Is there any way I can accept the package halahicly speaking. Can I ask the goy to sign it himself?