2. A race weekend is a three-day affair, with tickets sold for each day. What do you do on Saturday if there are no qualifs?
Can you imagine Monaco with no quali >_<
If it's based on past times that creates possibly a feedback loop but depends on details. E.g. can a swimmer use a non competition record towards their qualification.
Why should swimming be different?
In cases where some contestants have to be advantaged, the conventional solution in sports is to advantage the ones who performed better according to some metric.
I think it's unfair to reward those who were lucky or already advantaged somehow, but my wife who has a background in track and field thinks anything else would be unfair.
Why couldn't you shorten the pool, from a swimmer's PoV, by putting (say) a very shallow plywood box against the wall of the pool at one end of each "non-center" lane? Yes, you might need to do some math & stats to figure out just how shallow a box. Or, you could use a feedback loop - boxes start very shallow, leading swimmers get to pick a lane, boxes adjusted, repeat.
Would it be fairer to use randomly assigned lane? Then you get almost equal competitors in advantageous and disadvantageous lanes?
Isn't the top result in a year also used for qualification purposes (and thus lane assignment) for top-level competitions? Basically, you earn a spot in the best lane throughout the calendar year.