Bends and twists to blades, which are as often caused during hardening as later during use or abuse, are traditionally of no note/existence on the antique market unless very extreme indeed. This used to frustrate me greatly, as my interest in swords was initially a purely martial arts/practical use one. Likewise, with a partial exception for Japanese swords, quality of temper is of no interest to the antique market.
Damage should be disclosed, but can vary greatly in detail; you can always ask for clarification of, say "rusty but solid"
Slight wiggle to a hilt can often pass un-noted (especially by nonexperts) as a similarly unimportant/expected detail; if there were no explicit claims of tight and sound or whatever, there's not much to say there.
Keep in mind that on ebay for instance, you are buying from persons often without expertise or INTEREST in the item or its field, so the line of ignorance vs. negligence is much harder to draw than with a dealer.
As for what I find acceptable conditionwise, I prefer that at least one other collector somewhere would consider an item "ruined, just ruined" before I buy it
