2. Were the oil to be processed by American refineries, there is no evidence or statement of fact that the refined product would be used or sold in America (again, there is speculation that it could be shipped overseas, possibly due to quality issues mentioned above). In that scenario, America gets the pollution, the oil companies get the profits, and some other country gets the oil.
3. The number of American jobs seems to be rather 'manipulated'. Other non-oil-industry estimates are around 5,000 construction jobs, which would of course end when pipeline construction is completed. There is evidence and statement of fact that the job estimates by those who stand to profit from construction of the pipeline that their job numbers are "job-years"; for example, if 1,000 jobs are created for 3 years, then they count that as 3,000 jobs. FYI.
It should be noted that roughly half of the Keystone pipline project has been completed and is in use -- from Canada to Cushing, Oklahoma. One "XL" portion of the pipeline (phase 3) would simply run from Cushing OK down into Texas, and would be used to transport American oil as well. Phase 4 would be an additional pipeline from Canada to Steele City, Nebraska.