1 Tile Mapping - Layout tab -toggle grid-toggle snap to placement-toggle snap to resizing.
2 Message Box - Text object + timeline editor, there are examples in the forum.
3 Python - Python
4 RPG Events - "...anything RPG Related can be done in Construct,"
5 Menu Editor - Create sprite(right click-insert object-sprite) - click on sprite(use mouse and keyboard object- right click - insert object -mouse and keyboard) - go to layout.
6 Hud - Create Hud using sprites in one layout, then Inherit layer for your other layouts, using the inherit feature in the properties window. Use on your top layer for best results.
7 Save/Load - I haven't used it myself but there is a save feature in the events, have a look at that.