King's Quest has always had this formula of figuring things out on your own. I just recall the puzzles in KQ6 that irritated me. Given, I was only around 6 years old when I played it, I couldn't figure out the puzzles on the Sacred Mountain and it took me awhile to figure out what I was supposed to give the 5 dwarves on the Isle of Wonder.
Not to insult DaSkruff, but in comparison to the other KQ titles, the first episode was a gimme as far as progression goes. Although, I can understand your confusion if you had walked to the docks and hadn't picked up the cloak. It's just that adding some form of a hint would take away from the free-form adventuring that the series is known for. The most I could do is give you tips on what to look for.
You mentioned that using the 4 icons on everything that isn't nailed down would become monotonous in this game, while I agree, there is a method to the madness. For instance, in the hallway going down to the garden, I tried to pick up something off of the suit of armor (the lance or shield, heck, even the helmet would have been cool to use), but all I got was a comment from the narrator that said Graham prefers his tunic and tights to a full suit of armor. Clearly, the developers were aware that someone was going to try and pick something from the armor up, or else they wouldn't have programmed the animation and recorded the narrator's comment.
It's not about clicking on everything, just finding something that stands out, or looks useful. Also, if you didn't know to look in the garden for the cloak, I just stress that you must leave no stone unturned. I tried to open every door in the castle just to be on the safe side before I left the castle, but to no avail, only Graham's guest room was accessible. When I went into town, I searched in each pot, the chest, tried to access both the pawn shop and bookstore, talked to the doomsayer, tried to pick up the banner debris, etc. I spent a lot of time doing things that amounted to nothing, but it adds to the adventuring aspect. Besides, if you really get stuck, you always have us.