People ask questions of simple auctions for three basic reasons.
First, not everyone plays things the same, and there is a lot of ignorance. For example, in the sequence you quoted, 1
P 1
, are you playing Standard American? If you are playing Acol, for example, it means exactly the same as in Standard, but the asker may not know that.
Of course, the nuances may be different to you. I asked not so long ago about a fourth suit sequence. I know exactly how I play it, but I had no idea whether my opponents played it the same way. They refused to answer, which was unacceptable.
Second reason for asking is just to put opponents off. While this is very rare, if you find opponents are
always asking on every hand, how about looking for new opponents? In F2F the Director will stop harrassment.
The third reason is to establish a case for misinformation. There is little you can do about this sort of bridge lawyering except to grin and bear it. The Director will stop it in F2F bridge but you have no way of dealing with it in OLB.
So my advice is just answer the question, however inane, and do not worry unless it is continuous questioning.
As for your second question, answering "We have no special agreement" is absolutely fine, and several authorities have made this clear. If opponents moan, tell them they are wrong. But be clear, if you do have information, eg a similar sequence last week, tell them so, even if the sequence was not the same: that's partnership experience, and they have a right to know that.