Data Validation, drag and drop, auto population questions

[Phouthavongc]

Dear Excel Forum,

I am a complete novice at VBA...
and I am also relatively new to the forum.

That being said: basically, I want to know if it is possible to perform data validation both vertically and horizontally in a single cell so that a duplicate entry cannot exist in either direction (example given on Sheet 2... so that if a 'Company' exists more than once in a row or a column, I will know. If the same company exists diagonally, it does not matter).

I would also like to know if there is a code that will make it so that I can drag and drop a 'Company' from Sheet 2 into another cell, and if a duplicate exists of that particular company either horizontally or vertically, excel will remove the second instance with a prompt.
(If there is coding that can be made so that cells can be dragged and swapped with one another, that would be most helpful).

Finally, I would like to know if it is possible for data to be transferred from one sheet to another based on multiple criteria, or if it would be possible to auto-populate the second sheet based on Sheet 1's criteria (i.e. industry/product).

Sorry if what I'm trying to ask for has come out muddled... I'm not really sure how to word everything precisely to be honest.