So for now I give up. I'll still keep looking into other angles, but... I don't think it's very likely.
Literal
So now [topic-は] surrender [emph-ね]. Other [to-にも] still investigate-[try-てみる] [but-けど]... expectation-thin [copula-だ] [quot-と] think.
だから 'so / therefore' is the conversational conjunction. 降参 'surrender' as a standalone noun is used idiomatically for 'I give up.' 調べてはみる uses the ~てはみる pattern 'do X (as an attempt)' where the は scopes the て-form contrastively, implying 'I'll at least try, but...' — typical hedge. 期待薄 'expectations thin' is a compact Japanese idiom from 期待 'expectation' + 薄 'thin,' meaning 'not much hope.'