Hi Vinni,
To rename a column, the syntax is as below...
RENAME COLUMN <table_name>.old_column_name TO new_column_name.
Also when you alter the table to insert new columns, it would always be inserted at the end. You cannot specify the position.
I don't think that should affect anything as you can always select or insert specifying the column order like the way you desire.
If you really want to alter the table to insert the column in a specific position, then one workaround I could think of is to copy over the table to some temporary table, drop it and recreate it with the order you want and then copy over the data again. This is obviously not advisable 
.
Regards,
Anil