If you want to try and narrow down the culprit, try creating a new View Representation in your assembly and hide EVERYTHING. Then, choose a single part/component that you're fairly sure isn't the problem and make it visible again (making sure to set it's View Rep appropriately if necessary), and click the home view to see if it zooms in as it should.
If the home view zooms properly, start making more components visible (and with proper view reps) one or two at a time and clicking the Home view until you find one that throws the zoom way out. That component has something in it that's causing trouble!
Open up the problem component and fix any issues if possible, then go back to your main assembly and continue turning on components and checking home view zoom until everything is turned on and zoom works (or you are stuck with yucky view, but at least know the source).
When checking components for issues, ensure that they don't have any parts or components way off somewhere and that there are no sketches or work features which are very large compared to the assembly (this component will likely have the same "Home View" zoom issue).
When fixing sketches, check for things like orphaned points or center points on very large radius curves.
Orphaned points can often just be deleted (these are sometimes easier to find if your sketch is not fully constrained and you turn on the "Show All Degrees of Freedom" option while in the sketch).
For large radius curves, sometimes you can substitute in straight lines or 3-point interpolation splines (points at start, middle, and end of curve/arc) to get rid of the centers.
If you can't change some curves to remove centers, you may be able to copy the geometry into AutoCAD, convert it into splines, then copy/paste back into Inventor. There may be times where you're just stuck with those centers though.
For fixing work planes (or axes), check to see if "Auto Resize" is on or off. If "off", then try turning it on to see if it gets smaller. If not (or if it was already "on), then it's likely sizing to match a giant sketch (see fixing sketches above).
To force them smaller, turn off "auto resize" and then manually resize/move by clicking and dragging on the corners and/or edges (the mouse cursor should change when you're over the right area).
