Basically it is correct with that, but that is not all.
You knew that "それ" is a "pronoun(代名詞)".
But actually make rhythms in the story as an accent, also for switching to a new topic.
So, the word "それ" in this word refers not to a particular word or sentence,
means "the time zone that the something event occurred".
"でね、" is used women and children mainly.
"でさ、" is men mainly.
"でな、" is elders mainly.
"で、" is anybody used a lot.
"での、" is often used as an old era stories and older charactor's line.
All types are just not used for in formal.
In Kansai dialect, "それで、" changes to "ほんで、",
so become "ほんでね、" and "ほんでな、" even if young women used.
Kansai dialect talking speed a bit faster, you may hear "ん" sound has disappeared often.
Also, some other local(dialect) replaces "そう" with "ん", became "(そ)んで、",
but it does not used not so many for dramas etc,.
Also, first two sentences are some wrong and typo, wrote in Japanese.
1)
でね、カナダに住んでた時は好きだったんだけど、
今は毎日食べて(い)るので、なんかあまり好きじゃない。
or (if you are a woman,)
でね、カナダに住んでた時はあんなに好きだったのに、
今では毎日の様に食べるから、なんかもうあまり好きじゃなくなってしまったの。(or しまったわ)
2)
大好きなチョコ(レート or の)ケーキを冷蔵庫に入れたけど、
疲れて(い)たので(食べずにそのまま/すぐに)寝てしまった。
で、私が寝ている間に学校から帰って来た弟が、このケーキを勝手に食べていた。
早起きしてすぐ台所へ行ったのに、ケーキがなくなっていた事に一日中むかついた。
("Never mind." also included in that sentence?)
Although, the second one is drama's,
but I don't know whether the original was wrong or your hearing was wrong.
It does not matter not only between families, it often happens when share one refrigerator.
In Japan also write names in magic or stick a sticky note.(it has nothing to do with the q though.)
https://pbs.twimg.com/media/CsjA4IxVYAAxHyL.jpg:largeHave you ever heard Japanese famous saying,
"食い物(食べ物)の恨みは恐ろしい = Resentment of food is horrible"?
(= A grudge over food won't be forgiven easily.)
http://www3.kcn.ne.jp/~jarry/koji/kj037.html (episode of root)
It is probably worldwide that the scare of food grudges is common :)
http://stamp.bokete.jp/33407263.png
http://stamp.bokete.jp/10600943.png
で、どんな食べ物が好きではなくなってしまったの？
