PowerPivot 2016 DAX and Measures

I need help to solve the following problems on PowerPivot Excel 2016 Dax/Measures ………..

1 – Top 25 Vendors total spend,

2-  Top 100 items total spend,

3 – Average number of Orders placed to TOP 100 vendors and total dollars spend,

4 – Top 50 grocery items total spend (From groups of items like grocery, hardware, and homecare),

5 – How to count words starting with four lower case letters from a table column, words like: (archNICKLE, erstNESTIN, boesCRAFT),

6-To identify and count words containing lower case letters or upper case letters in a table column, examples (WESTbrOOM, BESTwesTERN,

7 – How to select and count MARITAL STATUS from table A, after comparing table A LASTNAME with table B LASTNAME (Table A and table B have many to many relationship, so PowerPivot excel 2016 will not permit creation of relationship link between them),

8 – My datasheet or report showing values 2, 10, 5, 20  from the table but when double-click to drill through, they display 1000 rows of data instead of 2 or 10 or 5 or 20 rows respectively,