Issues with importing from excel

Question

I have been running into a several issues with importing from Excel.
First my configuration
I am running SQL Developer ver 1.5.5 Build MAIN-5969
I am on a Windows XP Professional Version 2002 with Service Pack 3
I am importing into an Oracle 10g database.
1. SQL Developer doesn't work on Excel 2007, I have to save all my files into Excel 97-2003 format before I can use them.
2. If I run into an error loading and stop the process, SQL Developer doesn't release the Excel file and I get a sharing violation if I try to save the spreadsheet without closing SQL Developer.
3. I have found that I have to set print area to the area I want to work with, otherwise the import wizard tries to keep adding rows.
4. When using the Import wizard, it keeps adding commas on fields with numerics unless I specify the column in excel as text. Currently the column is formatted as General in the spreadsheet or I can change the wizard format to say the column is an integer, but it actually is just a code field with numeric characters so it may have leading zeroes that I need to keep.
This might be related,
I have a column in excel defined as text but only contains numerics. It is of length 4, but the wizard sets a precision of 5 with a datatype of VARCHAR2. If I try to change it to 4, I get an error saying the field is not large enough. Yet, when I do a LEN on the column, it only gives me a 4. I have other fields in the same sheet that a 3 position numeric and 2 position numeric and those are fine. I am thinking this is related to the comma being inserted in a numeric field for anything greater than 3 positions.
5. Importing excel dates to oracle dates doesn't work. I have to convert the excel date column to text then import as a VARCHAR, then convert to Date once in the database.
6. The default of nullible is not set on any columns and I have to set them before the import. (I would prefer it set to nullible and I have to uncheck the box to make it not nullible. I would prefer to import all of the data and then deal with the nulls after they have been pulled in)
7. When I select header columns included it uses that as the column names. Is it possible to do the name length check then? It has bit me a few times where I try to import and forget to check the name length and then I get an error when I start running the import.
8. If one of the columns to import has all nulls, then the precision comes out to 0 and if it isn't changed an error occurs on import. Could this situation default to a precision of 1?
9. It would be nice if there was a completion message displayed and a cancel option while running.

Answer 1

On point 3.
I have a column in excel that consists of numbers. 4 digit numeric codes. Ex, 1111, 2345, etc
The column's format is general. It displays as just 4 numbers.
When I start the wizard initially, the column appears with data as 1,111, 2,345, etc, on the Data Preview screen.
It determines the precision to be 5 on the column definition screen.
If I change the precision to 4 then continue, that field will error out when I verify with "not big enough to hold the data in source columns"
If, I change the excel column to a TEXT column.
Excel still displays as 1111, 2345, etc
The wizard then displays the same data 1111, 2345 on the Data Previeiw screen
Yet, when I get to the column definition screen it still sizes it as a 5
If I change it to a 4, I get the same error when verifying.
If I leave them alone as 5, then it processes just fine.