Hi braucheeinenJob,
That's enough information to tell me that the whole project is in a bit of a mess.
If "30% vests on the first anniversary of the closing date" then "% which vests on the first anniversary of the closing date" should be the header to the colum and the cell entry under that header should be just "30%". If the other entries in that column vary, then they should be put in different columns with different headers.
If you can do that, I recommend that you simplify the problem by looking at the various parts of the solution separately. Suppose that the number of shares is in cell A2, the 30% is in B2, the Closing date is in C2, then the formula if "IF(DATE(YEAR(C2)+1,MONTH(C2),DAY(C2))<TODAY(),A2*B2,0)" will provide you with the initial vesting based upon the criteria that one year had passed. A similar formula could calculate the 1.67% per month thereafter. Other formulas could deal with shares sold on specific dates, etc.
The key to all this is to present the information in such a way that a formula can be consistently applied to the various columns. This forum could heop with the individual formulas if you can present the problem in a clearly defined way. If you have a mixture of values and text in a single cell, that is a recipe for disaster.