- In theory no - it was designed mostly for small-amount-of-users apps. Your example shows it can be used in larger projects.
- The resulting system (if converted correctly) will be of better quality. But, as always in business, you have to mind the cost of conversion.
- Yes they can, but it is more difficult, as there are not many source control systems compatible with Access modules (Beyond Compare should work, afair)
- Performance, scalability etc. etc. I can think of no advantages, it's simply that VBA is not really good for larger systems (imagine that you would like to have some web reporting, or other functionality which is very difficult with Access)
- It's possible - but fully manually
As with all technologies, almost everything is possible using Access - but you have to mind the cost of maintaining such systems. It is not a question IF you will convert, but WHEN you will have to.