As mentioned in the comments, there is no general method for this, but there are certainly good ways to get started.
Note that copyright status is determined on a country by country basis, so "the country" in this answer refers to one you are living in, in this case Canada.
First, there's a quick test to determine if a work is definitely copyright. Most countries have signed the Berne Convention which provides for copyright lasting a minimum of 50 years after the author's death for literary works. In general, it also provides that a country treat works published in other Berne countries as if it were published in its own, with respect to copyright. I'll call this the equality rule. So we have that:
- If the country acceded to the Berne Convention before the publication date of the book and the author is still living, or died less than 50 years ago, the book is under copyright.
If the above did not apply, there are still steps you can take:
- Look up the country's copyright term. Find the legislation that established the copyright term. If the country has changed copyright terms over the years, the legislation will often provide for how books published before term changes are to be treated with respect to the new legislation.
- For Berne parties, does the country apply the rule of the shorter term? This is the main exception to the equality rule. The country may choose to use the country of origin's term instead of its own if it is shorter. If this is the case, then, you must read the country of origin's legislation with respect to copyright terms.
- The vast majority of legislation introduced affecting copyright terms has served to increase its length. Thus, if you pretend that the current copyright term applied back when the book was published, and find that the book is no longer under copyright, you can almost always assume that is actually the case.
For an example of how complicated this can be, see this analysis on whether public domain works in the US are copyright in the UK. The UK has been a Berne party from the start, but has at times changed its term length, and whether or not it applies the rule of the shorter term. The US has only been a Berne party since 1989. Before this, they required copyright registration and didn't always base the copyright term on the author's death.
In general, the factors you mentioned have the following effect:
- For Berne parties (as of publication date), this is only relevant for those applying the rule of the shorter term.
- Important to know this date when reading copyright legislation, as the applicable term often depends on this.
- Mostly relevant to pre-Berne accession, especially in the US
- Same as 3.
- Important, to know what laws ultimately apply.
- An additional factor you usually need: date of author's death (longest living author in case of multiple authors), as the term is based on this for Berne parties.