pgAdmin vs SQL Server Enterprise Manager

I am working at a company that has been using MS SQL Server, and we are going to be switching over to postgresql next week. (Getting off of Windows will be a relief!)

I am very familiar with SQL Server's "Enterprise Manager", which is their GUI for accessing the db. I have been acquainting myself with pgAdmin. There are a number of things that I really like about pgAdmin, but there are a few things that SQL Server Enterprise manager can do, and it's not clear to me if pgAdmin can do them.

Can anyone let me know how the following things are done in the postgres world?

1) With SQL Server Enterprise Manager, I can change a column's type. For example, I can change an int column to a float, and SQL Server automatically converts all of the int data to floating point data.

2) With SQL Server Enterprise Manager, I can copy and paste rows. There are two scenarios:

2a) Suppose I have a table that has some primary key, and it has a large number of non-null columns. Inserting a row can be tedious because I have to specify all the non-null values. What I often want to do is to duplicate a row, change its primary key, and perhaps modify 1 or 2 of its other columns. With SQL Server Enterprise Manager, I can copy a row into a "new row" buffer, modify its primary key to ensure uniqueness, optionally modify 1 or 2 other columns, and paste the result into the table.

2b) Suppose I have two or more tables that have identical schemas (column names and types, primary key). I want to copy a set of rows from one table to another. (I've already verified that there will be no primary key conflicts.) With SQL Server Enterprise Manager, I can copy a set of rows from one table and paste them into another table.

Any help would be appreciated!

-Mike Wertheim