1. Random donations - a percent of the sum depending on the available outputs. The user will be able to select the approximate desired amount for donation: from 0.1% to 10%. If there is a change input close enough to the target, it will be used as a donation.
2. Donation mining - the user who is mining in pools from the GUI Wallet will be be able to specify donation address and percentage of donation mining shares (0-100%) that will be contributed for any donation.
It reminds me of Bytecoin's donations in their GUI Wallet, but they are closed source. Are you going to replicate this features?
Also, is there a GUI Wallet with mining on Forknote?