I've been playing around with a point and click adventure game, too. It's a bit of a mess to be honest, and I plan on redoing it in a far cleaner manner, but I'm sure there are plenty of ideas, methods, things of that nature that might help you out a little.
I have an inventory, a skill system, a HUD, a combat system, enemy AI, condition sensitive mouse cursor, and some other neat little details going on in this little thing. The game is controlled entirely via the mouse, with the left mouse button being used for movement, attack, item pickup, skill/item use, so on and so forth, and the right mouse button being used to stop movement or cancel out a skill or item or melee attacks if the mouse is over an enemy.
It's a cool little demo (at least I think it is
) of my master project that I'll likely never finish. I plan on using Construct 2 for it when I get around to restarting it, but I'm also working on another Construct Classic project right now that's almost finished, but yea, Classic is fully capable of point and click adventure games games. Proof of concept I guess.
I don't recommend all the methods in this, but like I said, could give you some ideas.