I like the suggestion of having zoom go to the mouse cursor rather than the center of the screen. I would prefer to see the minimap remain, however. I don't like the idea of having to zoom out in order to scroll large distances, especially considering the only other reason I would ever zoom out on a level are to get a higher resolution overview of the level than what the minimap provides.
As for scrolling:
With minimap:
Click where you want the screen.
With zooming:
Zoom out.
Click where you want the screen once you've zoomed out far enough.
Zoom back in.
Zooming in place of the minimap changes a 1 step process to a 3 step process.
Furthermore, losing the minimap impedes the ability to have a basic idea what is happening to offscreen lemmings. I don't zoom out while I'm actively playing the level (rather than just looking at the level, maybe thinking about how to solve it) because then things start getting annoyingly small to look at. The minimap is quite helpful for having an idea of what the lemmings I'm NOT currently focused on are doing. Are they contained? Are there some approaching a cliff that will need attention soon? Is there a trap offscreen killing lemmings? Is an offscreen digger/miner/basher about to finish? I don't like zooming out on whatever I'm trying to focus on - things get too small to comfortably look at.
I do concede that the minimap has issues with some sizes of levels that I'm not entirely sure how to fix. Certainly, as much of the level as possible should be displayed on it.
A quick clarification of my specific usage case:
The minimap is used for:
1) Scrolling - I prefer using the minimap to scroll if one is available rather than zooming out/zooming back in.
2) Situational Awareness - I like to be on the current default zoom while focusing on specific lemmings. I use the minimap to have an idea of what offscreen lemmings are currently doing in order to determine if my attention is needed elsewhere. This behavior is further reinforced by another game I play, Starcraft, where the minimap is extremely important for determining where your attention is needed.
For these purposes, I like to have the minimap in low-res mode. Part of this is because I'm used to it since it's been like that for a long time. The other part of it is because its generally brighter colors are more easily read - for what I use the minimap for, I need to be able to clearly see where the terrain is and where the lemmings are. If high res minimap used the same colors as the low res one (i.e. one color for terrain and one color for lemmings) I'd be more likely to use it. As it stands now the high res minimap is blurry and somewhat difficult to read.
I use zooming out for overviews and route planning, when I'm trying to take in the whole level and decide what to do. I don't usually use zoom in (further than default, anyway) in sprite based games except for getting a closer look at the artwork.