No you could not walk. There is no hotel close enough to the Magnolia to walk. You could take the trolley, it goes right past the West Village and it stops in front of the Fairmount downtown, so you could walk and take the McKinney Avenue Trolley to get downtown to the Fairmount Hotel. There is a nice steak house within walking distance of the Magnolia Theater called Texas Land & Cattle, at the corner of Cole and Lemmon.
If you wanted a theater, restaurant and hotel within walking distance of each other, you'd have to go to Northpark. The Bradford Hotel is across the street. Another nice feature of Northpark, there is a shuttle that will take you to the DART rail station.
Hope this helps!!