First of all, Pumaman is "This Chris guy", and you don't have to use AGS, but you'd be missing out on a great program. Everything you listed is possible, though I didn't understand what you meant in number 4. What main screen? Please be more specific.
Now, about the custom inventory, here's a good tutorial:
http://ags.slaveinostudios.com/customize.html
Thi includes selecting the inventory item too. What do you mean by interacting? This is ussually the same as selecting. Do you want this to be something else?
Please clarify what you mean by number 4. Do you mean the main menu? What do you want to select there?
Now, about the custom inventory, here's a good tutorial:
http://ags.slaveinostudios.com/customize.html
Thi includes selecting the inventory item too. What do you mean by interacting? This is ussually the same as selecting. Do you want this to be something else?
Please clarify what you mean by number 4. Do you mean the main menu? What do you want to select there?