It is too inconvenient to press “shift+enter” after selecting a child object with “cmd+click”.
Is there a way to choose quickly with just “keyboard+click”?
Is there a shortcut in which the property panel is focused like alt+tap in the sketch?
Is there a way to adjust the size to what percentage of the parent frame? (For example, a method of adjusting a current object to 70% of a parent frame)
Shift+ Enter is probably your best bet here. Outside of that you could right click and use the context menu to select the parent element that way. Also possible but definitely longer would be to use command+/ to open the quick actions menu where you can type and run “select parent”