There is an enormous amount of good and bad advice on the boards here. Exercise caution.
Yes, if they were difficult to achieve--
This, IMO, is no function of a CMS--it gets used once and is probably close to impossible to write in a sufficiently general way to be widely useful. This part I think you will have to have custom built whether you use an existing product or not.
It's also worth considering that a) if the CMS you wind up using can exactly mirror your directory and file naming conventions, you don't necessarily need to import any page until it needs changing (unless you're proposing a design change at the same time as the implementation) and b) that it's quite possible it will be cheaper to migrate content by hand than it is to write a new tool to do it quickly--5000 pages may or may not be a large number, depending on what they're like.
This feature is available and quite mature (i.e. has been in production use for three or four years already) in at least one CMS I know well. A quick look on one of the various CMS comparison sites shows that many products claim multi-language capabilities...
These are plain, bog standard, common features in the better products out there.
This is what worries me about people getting into major CMS projects without doing their research--all of the features that you have named (at least those that you could reasonably expect to be generically useful) are widely available, but you're preparing to start from scratch.
Build from the ground up if you need to, but make sure that you need to before you start.