As a native Kansai-an I have to point out: the natural way to say it is:
It'd be odd to say "しちゃあかんで" as you don't say しちゃ in Kansai dialect.
”してもうたら” has a slightly different meaning and shouldn't be used in this case. "してもうたら" is used to describe the consequence of an action, e.g. 火遊びしてもうたらもう許してもらえへんで ...
What you're seeing isn't any kind of "dialect spelling" or "pronunciation spelling", but rather the historical spelling. Historical spellings are the kana spellings from before the spelling reforms of the late 1800s up through the mid-1900s. These older spellings often reflect the etymologies (word roots) of the terms.
For more about ...
じょ used to be a very common sentence-ender in Awa (Tokushima) dialect, although it's becoming obsolete, like other dialects. Looks like じぇ is a sentence-ender in Iwate dialect.
That being said, this character's speech is not dialectal at all, so basically this is just another unique キャラ語尾 used to add flavor to a character.
Some キャラ語尾 are "recycled" ones ...
Yes, this よか is a slangy variant of よりか "(rather) than ～", which in turn is a colloquial version of より. See this entry.
Wikipedia says this is originally nothern-Kanto dialect but has been accepted as part of the language spoken by modern Tokyoites. I personally never use よか regardless of the formality, but I know a few people who actively use it ...
This 期待されとる is short of 期待されておる (see this chart), and in this context おる is the same as いる for progressive aspect. なんぼ is the equivalent of いくら in Kansai/Shikoku dialect. や is widely used instead of だ in western Japan.
= No matter how much you are expected (No matter how much they expect on you), if ...
My grandma, who was born in Taiwan around the 1930s, speaks Japanese as her first language. Apparently she says that although the language hasn’t changed much, there has been many new colloquial words introduced which she doesn’t understand. But still, it’s probably just like talking to any Japanese grandmas. As to accents, I don’t know.
This だって is a word recognized by dictionaries. It is a part of the Standard Japanese vocabulary and safely understood in casual conversation without showing peculiar color, if not everyone from every region uses it spontaneously.
I think it's a mix of the two: a "dialectical" (or perhaps just personal) "pronounce ぞ/ぜ as じょ/じぇ" thing (but only specifically for the sentence-ending particles).
I feel like, in fictional media like video games, manga, and anime, sentence-enders are the very first thing that gets "tweaked" to indicate some sort of dialectical or individual, quirky ...