Fortunately, replying to your own post does not make the post appear at the top of the list :-)
all the methods you mentioned work, but the queruestion you should be asking is: how easy is it to work with them?
How much extra work is there for each method?
For ex: if you have a seperate database for each language, you can switch languages by changing the name of the database that you use. But, you will have independant databases. If you decide to add a record to one database, you must add it to all the others, or the script will fail when it uses another database.
What if you add another language later?
What if you need to translate to a language that you don't know, and you need to send the data to a third party for translation, how easy is it to export and import the data?