1. Can Zope handle a site like this (items 1-3) ?
Yes easily. Since most of your content is static, it would be easy to put Squid or some other cache in front of Zope, so that most of the traffic is handled by the cache. Any hits to Zope could be handled by a ZEO cluster. Between ZEO and Ram caching and some well thought out squid caching you can get a high performance site.
2. Can it handle the update (items 4-5) ?
Yep, storing a 1mb image that changes every 15 minutes to the zodb, would be fine, but the database would grow in size. You would want to pack regularly or preferably run a non-undoing storage such as BerkleyStorage.
3. Is it possible to give a rough estimate of the amount of work to bring this site under Zope's CMF (working hours) ?
Not really, but I think it would come out much cheaper than the six figure range. There are many consultants who could happily help you with this. If you are going to use CMF I would always recommend looking at Plone as a much easier UI to configure. However from the requirements I couldn't really see a need from CMF let alone Plone. -- Andy McKay Agmweb Consulting http://www.agmweb.ca