Is it permissible to request a written acknowledgment of the sister's share, the value of which was paid to the father? And is it permissible to request a written acknowledgment of a plot of land equivalent to the value of the sums paid for the sisters' marriages?

If you spent on your father or siblings as a donation, you will have a great reward, and you have no right to reclaim what you spent. However, if you spent with the intention of being reimbursed, then you have that right according to the majority of scholars. There is no harm in asking your father to grant you something from his wealth, and this is not considered a forbidden preference as long as it is in exchange for what you spent.