Panel Schedule Macro

I would like a macro that merges or unmerges cells on two sheets based on an adjacent cell value (1, 2 or 3). I also need it to hide a series of rows on two sheets based on a different cell value. For example, in the attached file, if cell G8 on sheet MASTER is changed from 1 to 2, cells A8 and A9 would merge, cells F8 and F9 would merge and cells G8 and G9 would merge on both Master sheet and sheet PRINT. If G8 is changed to 3, A8, A9 and A10 would merge, F8, F9 and F10 would merge and G8, G9 and G10 would merge on both sheets. If the G cell is changed back to 2 or 1, the A, F and G cells would follow suit. Likewise the same operation is required for cell L8, L9, and L10 merging and unmerging the associated cells in L, M and R. This operation applies for all rows 8 through 28. I also need to hide rows 17-28 on sheets MASTER and PRINT if MASTER cell A3 is selected as 18 or hide rows 23-28 if Master cell is selected as 30. No rows are hidden if Master cell A3 is 42. In the end of any macro operation, sheet PRINT needs to be in a protected state. The password to unprotect sheet PRINT is "unprotect".