Thank you very much for playing and offering some great thoughts on the game!
Feature-wise, more roads are on their way! They'll never get super complex but intersections will definitely be included. Water is also planned at some stage.
The grid snapping is already working as envisioned, but the leniency of where it will actively allow the player to click can be adjusted super easily (set it up to do so), so maybe in the next build I'll adjust this. Hopefully that helps the usability issue you speak of! I'll also give some thought to the keyboard shortcut grouping when I implement the planned UI.
Again, this sort of feedback is extremely valuable so I really do appreciate it (from everyone). Thank you also for the kind words - it's hugely motivating hearing that my work can bring joy to others :)