高【たか】 means "yield/amount/quantity" (e.g., of a crop). くくる means "to bind/tie" and, by extension, "to summarize/consolidate". Thus, the literal meaning of 高をくくる is nothing more than something like "to estimate (the capability of someone/something)" or "to assume". However, as an idiom, it has gained a derived ...
are all variations of a set phrase meaning "it's nothing" "it's no big deal". Here どう is just the usual question word and って or と the usual quoting particle. Literally the phrase means that it is not something you would ask/enquire about by saying どう.
条件付き means "conditional, conditionally". It comes from 条件が付く, 付き being the 連用形 of 付く and thus used as a noun/prepositive modifier. The operation is conditional.
From their FAQ:
Q: What kind of operation is "conditional operation"?/...