Both of those settings are controlled by Word.
In the Preferences, you can set up the default locations for various things in the File Locations tab.
When I resize the Open file dialog, it stays the same as the last time I opened it.
The only thing I can think of is the preferences file (plist) is corrupt and not saving the settings. They appear to be in each individual app plist file.
You can reset the Word plist to defaults and test. Move the com.microsoft.word.plist to your desktop so you can move it back if it doesn't help. The file is ~/Library/Preferences/com.microsoft.word.plist
If your Library does not show in your Home folder, hold down the Option key (labeled alt on non-US keyboards) and select Library from the Go menu.
Note that this will reset all of your Word preferences to their defaults. That is why I suggested moving it as opposed to deleting it.