Replacing LVL beams by some lower depth ones
Probably not.  Height adds much more strength than width does.  A beam that is 1 3/4 x 11 7/8 has an I of 975 [I = (b*h^3)/3].  A 7 1/4" tall beam would need to be ~7 3/4" wide to provide roughly the same capacity (as @isherwood said, WE ARE NOT PROFESSIONAL ENGINEERS).  This seems that it would be more inconvenient to your design.