What obstacles are there to you as an American living in Toronto/Canada or spending prolonged time there?

I am a Canadian living in the U.S with my American wife.  We came to Canada to visit my parents 11 days ago.  We were pulled into secondary and were there over an hour.  You have to have a very good reason to cross into Canada. We are here to help my elderly parents so it was ok.  I am a Canadian citizen, so they can't refuse me entry.  Since my wife is married to a Canadian citizen, she was able to cross WITH me.  However, you are subject to an interview with a Health Canada nurse, who will question you and inform you about Covid.  You will also have to quarantine for a 14 day period, which includes downloading a special app, 'ArriveCan'.  Every day you have to open the app and check in. They will fire questions at you about where you're quarantining and how you're going to get food, etc.  Also, Health Canada will call you a few times in this 2 week period and check on you.  If they are suspicious that you aren't at your place of quarantine, they will send a rep out to make sure you're there.  If you're not, you are facing a big fine and possibly jail time.  (This is what the nurse told us.) This is my 3rd last day and I am going crazy!  We crossed on land, but if you fly in, you need to show a negative Covid test upon boarding. 

During normal times an American can go to Canada and stay 180 days without much problem 

However since the Trump administration so screwed up the pandemic response Canada closed its borders to US visitors months ago and show no hurry in reopening  them

Prior to the pandemic a US passport holder could spend up to six months in Canada as a tourist. But with the border closed now and Canada not interested in Americans trying to enter you wouldn't be allowed to go to Canada at all. 

Please don't feed the troll.  Don't answer.  They go away when ignored. 

Americans can normally stay in Canada for up to 180 days with no issues.  However, the borders are closed right now for all "non-essential" travel, which includes a visit like what you are proposing.  Being responsible means not letting people in who may have the disease.

US citizens have unique privilege of visa-free entry to Canada (& vice versa for Canadian citizens to US) for up to 180 days in any 365-day period. But that is for TOURISM/vacations ONLY. To live & work in Canada, you must either hold a temporary employment visa - obtained by a govt-authorized employer in a listed shortage occupation - or qualify to immigrate & be approved for PR (legal permanent residency status) prior to entry. 

So what are your qualifications? What degrees do you hold in which field from which universities where? What post-master's (preferably doctorate or professional) degree experience do you have doing what, exactly, how well & how long for whom where? Is this in a listed shortage occupation, and can you compete with 100-1000 (or more!) qualified applicants from around the world to get hired by an authorized employer willing & able to apply for your temporary employment visa or support your application for immigration?

Depends if you're going for leisure reasons or to work.

No tourists are currently permitted... so you won't get in just to 'wait it out'

Your 'good idea' won't happen........ travel is very limited and restrictive because of covid so 'good idea' is not a reason Canada would allow you to go

Normally, that would be fairly routine a thing to do, but the border has been closed for all but essential travel for almost a year now, so I doubt you can get it just because you want in.  Even visiting family is tough to get approved.