When creating spreadsheets or statistical papers.
Microsoft Word is a word processor. Microsoft Excel is a spreadsheet application.
Microsoft Word is used for writing papers, and Microsoft Excel is for spreadsheets.
Microsoft Word would be for creating word processing documents and Microsoft Excel would be used to create spreadsheets.
Yes
Excel and Microsoft word are two different programs. To ask how to you use excel for typing ms word does not make sense
You would use Microsoft Word for mail merging.
Microsoft Word and Microsoft Excel documents can be linked to each other, so that changes in one document will show up in the other. So it is possible to enter data in Microsoft Word and have it appear in Microsoft Excel. It is also possible to do formulas in tables in Microsoft Word, without linking to Microsoft Excel.
The closest equivalent would be Pages, although it doesn't have quite as many features as Microsoft Word.
Microsoft access+Microsoft word+Microsoft excel
If you open it up and go to the help features you would have a hard time not understanding how to use it within 30 minutes. It really straight forward to do basic things. But like anything the more complex the usage the more complex the knowledge required to use it in that fashion. Overall It is fairly simple. --edit I suppose that is assuming you have basic computer skills and are at least some what experienced in the usage of a computer and menus, biased on the ability to post this question it was assumed.
Microsoft Office
No they are not interchangeable. There are things that both can do, but Microsoft Word is a word processor and Microsoft Excel is an electronic spreadsheet. So they are both designed for different kinds of jobs. You can copy things between one and the other, like if you have a report in Word, and wanted to include some figures from Excel. Microsoft Word is for working with text and Microsoft Excel is for doing large scale calculations and other numerical analysis and manipulation.