Does the ruling against the impermissibility of selling live animals by weight—due to gharar (uncertainty/deception)—apply to selling fruits with seeds, such as dates and mangoes?

There is no problem or significant gharar (deception/uncertainty) in selling dates and similar fruits that contain pits or seeds. No one has ever stipulated that the pits must be removed for the sale to be permissible. Minor gharar that is ancillary is forgiven by scholarly consensus. Gharar and ambiguity are of three types: extensive, which is forbidden by consensus; minimal, which is permissible by consensus; and moderate, which is disputed. Muslims have unanimously agreed on the permissibility of things that contain slight gharar, such as selling a padded robe, renting a house for a month, paying to enter a bathhouse, and drinking from a water-skin for a price. The basis for invalidating a sale due to gharar, and for its validity despite it, is as follows: if there is a need to commit to gharar, and it cannot be avoided except with difficulty, and the gharar is slight, then the sale is permissible; otherwise, it is not. Minor ambiguity is overlooked, and hardly any contract is free from it. As for the issue of selling a measurable ribawi (usurious) item of the same kind by weight, that is another matter entirely unrelated to the issue of gharar.