1. Inflexible - "Your thinking is inflexible"
2. 死光光 = Here 光 means empty. The doubling of the character is to put emphasis as a state of emphasis. So it means "all dead" There are many other examples... 白雪雪 So white that it looks like snow i.e. ultra snowy white. 光秃秃. Here 光 means "bare", 秃 = naked, without hairs - thoroughly naked.
3. 过来 here means "to turn over", 顾 = care (other meanings include, to look back, take into consideration, attend to). Literally it means, "utter despair or so dire that one cannot even turn his body". So the translation of the sentence in the given context is, "we can't even fend for ourselves anymore". 老记 is a dialectical term and means different things in different dialects. In Cantonese, it means "reporter" or "a very close friend". 老 here is a honorific, to signify experience. Unlike western culture, old age is a sign of respect and not youth oriented society.