As for the auto-zoom issue, understand that the XLIQRoutes2 is one of the last of the 'old series' of units built on what we here sometimes call the Nav2 platform. Nav2 devices connect to your PC and appear as external drives and can be manipulated as such. There are also some features that are missing on Nav3 devices that existed on many Nav2 devices. I'd say that itinerary planning was one of them, but your IQRoutes2 can't do that natively, either.
The newer units on the Nav3 platform CANNOT be accessed like an external drive, and a few of the old features are missing (e.g., the itinerary planning I mentioned above).
So before I dare recommend something new to you, I need to know a bit more about your use model and whether the purchase of any of the newer Nav3 models is going to put you into a real bind or make you happy. If you are depending heavily upon any of the Nav2 features that are missing on Nav3, you might find that looking for a used unit of another flavor might be more suitable. TomTom has been in a platform transition for more than a year now, and while certain 'missing' features have been returned, it has taken a while, and some still aren't back.
As to auto-zoom in particular, it's a mash. Some units auto-zoom by default in both 2D and 3D or just one, and some allow you to disable it in some modes.
Older (Nav2) models:
IQRoutes2 = auto zoom in 2D and 3D, no configuration
IQRoutes = auto zoom in 2D and 3D, no configuration
GO models (550, 750, 950) = separately configurable in 2D and 3D
Newer (Nav3) models (GO8XX, any GO model with 4 digits, all Via models and the Start series - these are all 2011/2012 models) all include the ability to separately control whether the device auto-zooms in 2D and 3D modes.