As a rule, the more questions, the fewer answers. Many of the questions cannot be answered definitively, but the answer to #2 is yes and most people probably don't deem chinos/khakis "odd trousers." If they're colorful, they likely are too casual for wear with cufflinks. Also, whether a blazer or jacket is formal enough for cufflinks depends on many details - for example, patch pockets are casual and point toward no.
4/11/14 at 12:37pm