Returning to UK on Visitor Visa after YMV expired

After months of scouring the internet for resources and advice, some good, some horrific, I am hoping to attain some direct advice on this matter....

I am a Canadian citizen who has been living in the UK for the past 2 years on a Tier 5 Youth Mobility Visa. Understanding that there was no possible way to remain in the UK once my visa expired, I returned home to Canada where I now reside. While in the UK, I fell in love with the area(as well as a wonderful British man, of course), and am now looking at the possibility of returning for 6 months on a Visitor Visa to visit and figure out our next step.

The intention of my stay would be to visit the British seaside for 3 months, and then potentially travel to France and Italy to volunteer for 3 months.
No other Visa options are possible, as I am not looking to reside in the UK for the long term at the moment.

As a Canadian, I do realize that it is not necessary to apply for a Visitor Visa beforehand, but I am worried that as my YMV Visa only expired 2 months prior, that they may decline my entry

Will this be a potential problem at the boarder with an IO?

What documents should I be prepared with to prove my purpose for visit and plan to return home to Canada after 6 months? I know it will look suspicious returning so soon, but if I have an itinerary and plans only to visit(I was unable to spend a summer by the sea as I had to return home to Canada last summer for a family emergency), would this help my case?

Also, am I even allowed to leave the UK to travel the EU and then return to the UK to fly back to Canada?

Any help or advice is greatly appreciated!!

Many many thanks.

K