Do colleges look at senior fall grades during redular decision?!
Regular
Of course they do.
Your senior year course rigor and grades will be reviewed as part of the admissions process.
Yes. Typically your HS will file a mid year report with yoyr grades. Now… I assume some schools have already made at least a tentative decision, depending on when that report arrives. And obviously rolling admissions schools may decide before getting it.
It depends what colleges you’re talking about. Large public universities often don’t but they do check your final grades since any grade below C usually means being rescinded.
Private universities and LACs use feet semester grades.
Feet semester grades? Great typo 
Most schools will want to see mid year and final grades.
And most cover this somewhere in their web pages.