Re: Mouse roller zooms instead of scrolls the image
Scroll whell behavior can be changed in "File" -> "Preferences" (see tab "General", option "Mouse Wheel Behavior").
Re: Grouping of objects for reuse is next to impossible
Would you care to elaborate that statement? Grouping nodes is supported as well as copy-pasting of grouped nodes.
Re: Pasting of grouped objects only pastes back within the parent group making groups nearly useless for large projects
When you use "Paste" from the (right-click) context menu, the copied objects will be pasted at the current mouse position. If you do not want the pasted objects to be assigned to a group, make sure to right-click some empty space.
Re: clicking on an object to select does not always work, yet clicking outside the object always drops in a new object (which then has to be erased).
Would you care to elaborate in which circumstances clicking an object does not select that object?
Clicking on empty space does not "always drop a new object". If there is at least one selected element, clicking on empty space unselects all selected elements.
Moreover, whether or not a new node is created when clicking on empty space may be configured in "File" -> "Preferences" (see tab "Editor", option "Create Node on Background Click").