1. I believe the blue vacuum hose should go to the vacuum ball located behind the bumper on the passenger side.there should be another hose connecting the two.The heat/ ac selector is a cable located under the passenger side of the dash make sure it's hooked up . The two are not related but if you can't change to vent / defrost etc . The blue vacuum hose being unplugged is you culprit .
2. That's a plug for lowwasher fluid which is not used to my knowledge on Mjs but is used on xjs
3. That's is the optional under hood light plug . Being I don't see one on your truck it's good where it's at.