Tips to SQL Server Fast Performance

Question

Sir, I need your help in the following subject.

has data Type declaration a major role in the performance?

suppose I gave data Type varchar(max) to column 'Gender'. As Gender comes only 4 or 5 characters, is this absurd to give varchar(max)?

Like that could you send me data Type to be used for the following:-


1) primary key,

2) Name,

3) Address,

4) rate(for decimal points also)

5) quantity.

6) discount,

7) tax,

8) phone number(with 14 digits),

9) country,

10) currency,

11) date,

12) age.

 Please reply with giving appropriate data Type to these coulmns.