1. the weekends are not enough to keep PR. Count the number of days you can stay in Canada, it probably won’t meet the 3-year every 5-year requirement
2. What’s your visa in the US? H1? And what’s your country of birth? These will have an impact on your status in the near future.
3. For me, the experience was good - with a NEXUS card, going back and forth is quick, no question asked at all, just a ‘welcome back’ from the officers. And I enjoyed every visit to Vancouver with family and delicious food in numerous restaurants