Ephraim and Sheila Urevbu have ambitious goals for their renovation of 412 S. Main Street. The space, they hope, will soon be the home of art business instruction, in-depth community conversations and a restaurant from the minds of Ephraim Urevbu and one of the city's most successful restaurateurs. Since Onix restaurant moved out of the space last year, the Urevbus have already invested $60,000 cleaning up and overhauling the space to better accomplish their mission of "diversity through the arts." "The…