1) Yes you can

2) you can have 1024 columns in a table

3)These two languages are functionally equivalent which means that they each provide equal abilities to create Web applications. The differences between the two languages are syntactical and stylistic.

Visual Basic programmers will be more comfortable developing Web applications in Visual Basic .NET; C or C++ programmers will be more comfortable developing with Visual C#.

VB.NET is not case sensitive .But C# is case sensitive.

C# use braces ( { and } ) to declare functional blocks of code.VB.NET doesn't use braces .

In VB.NET implicit type conversions are permitted by default.
But in C# type conversions are performed explicitly by casts

In VB.NET array elements are specified using parentheses.
But in C# array elements are specified using square brackets.

In VB.NET u can omit parentheses after method names if there are no arguments.But in C# u must include parentheses after all methods.

In VB.NET all statements are terminated by carriage return.
But in C# all statements are terminated by the semicolon (;).

In VB.NET statements are continued using the underscore (_).
In C# statements continue until the semicolon (;) and can span multiple lines if needed.

VB.NET use the ampersand (&) or plus sign (+) to join strings.But C# only use the plus sign (+) to join strings.

I have taken the above details from a text .

u can get some information from the following links.

http://support.microsoft.com/?kbid 308470
http://www.harding.edu/USER/fmccown/WWW/vbnet_csharp_comparison.html
http://www.dotnetspider.com/kb/Article1540.aspx
http://www.dotnetspider.com/kb/Article1541.aspx
and
http://msdn.microsoft.com/library/?url /library/en-us/vsintro7/html/vxgrfLanguageEquivalents.asp