Just to clarify, you'll be applying for permanent residence first (not citizenship). Since you are from the US, you should apply outland (not inland). Outland is way faster for Americans. Also, if you apply outland, you don't have to stay in Canada without leaving while the application is being processed. If you haven't done so already, read the first post in the following thread. It has info that will probably help.http://www.canadavisa.com/canada-immigration-discussion-board/spousal-sponsorship-t46995.0.html
As for visiting... There's no easy or clear cut answer. The reason why you are running into problems is because once you are spending more time in Canada than outside of Canada, you're really behaving more like you're "living" here rather than just "visiting". (Many of us on this forum have been through this and there's a very fine line you have to try to walk when you want to stay here for long periods of time.) Sure, you're following the rules by not working, etc. But at this point you're spending way more time in Canada than a visitor normally would and this is what has caught the attention of immigration. Simply put - you're not allowed to live here as a visitor. (And yes - I know how much of a mess this creates. My husband went through it as well.)
Your best option for the next border crossing is as follows:
- bring proof that shows strong ties to the US
- bring proof of your departure flight (assuming you're flying)
- pay the spousal immigration fees and bring proof that you have done so (this shows that you have plans to change your status to something more premanent)
- bring proof that you have started completing the sponsorship application (or preferably - bring proof that it has already been submitted)
Hope this helps at least somewhat...