Hard one! Everyone with expierience looks this way.

I'm just wondering if it is possible to make random events.
Like percentence chance of something happening.

Other than that I need help with scripting. I'm looking for a few things:

*Jump - >I have script but where do I put it?

*Swimming - I could just fix this with alot of event stuff but I'd prefer
script.

*Speed Potion - I've made a consumable item called speed potion
that increases your speed too maximum. I need help making this only
lasting a while.

*Zelda combat system - Instead of entering a combat menu I want
the character to be able to just press a button and attack
(No damage system needed; they die in one blow).

*Tileset mergeing - I need to put in doors to Caslte Town.

*Fishing - Need graphics for fish and rod. Also need to know where
to put the script.

*Common Events - How do I make events that effects a certain
area around where it is triggered (for example; I use a bomb
that will kill all nearby monsters).

That's all! Don't need replies on all though. Hope for some reply.. -.-