Yes, I frequently do this with a modal form with no problems and no erratic behavior. Modeless operation where you are trying to interact with the Revit user interface is where there is trouble. As long as the link is one way there is no trouble. The one-way link can also go the other way. For example an add-in can use a Form ( a "borderless" WPF is what I use) as its feedback display window during the add-in's workflow steps. The WPF is fired up by the add-in, which instructs the WPF to change its displayed contents, ie. feedback to use, instructions etc, as the add-in runs. Meanwhile the WPF, its own floating entity, can get user focus to be positioned and resized by the user as he or she likes it. It can also save that information to its own settings for the next time it is fired up. The WPF is in its own little world. Revit is in its world, but it can control the WPF. The add-in closes the WPF when it finishes its Revit operations. The user no longer has to constantly look down to status line to figure out what state Revit is in or what the current prompt is reading.
Back to this problem. I am seeing odd things happen when manually renaming views.