Wao this is the hard one. This is quoted from Manga(cartoons) or something I guess. The direct meaning of the sentence is "I am not at the same dimension(means at the diferent level) youll see on every corner for god's sake!!" or something like that. Inside the bracket, it says "I mean two dimensions". So translating just this one sentence is difficult as we cant see the context. そんじょそこら is a spoken slang to emphasise "そこ（there)" which always joints with negative sentence. For instance 「そんじょそこらのものじゃない」 = this is not the thing you can see everywhere. 次元=dimension. could be 'level' or 'category' when you use it towards people. I am not confident enough about my explanation but hope it could be a little help to you!

同じです。Both meaning is "I like eating". Grammatically the former is sligh~tly polite but really not much difference in its meaning.　と私は思います。 私も食べるの大好きです；-)

"mama" is "leave something as it is" or "let it alone(be)". It could be "with something on" if the subject is nown. Hope it helps!

Yes they are almost same as "quotations" in English. 「」 are mainly used for colloquial sentences, also for proper noun when you want to emphasise it. <> are just a style I think.

私は渋谷に住んでいます。日本に住んでたことがあるのですか？