i don't want to be harsh or something, but this sounds more like "I want to make an RPG!"
but still, here are some suggestions-
For special effects, use the 'plasma' and 'particle' effects object, these can be used to make almost any kind of effect, you just need to experiment with the values.
Alter laws of physics-
hmm....i really can't understand what you meant by this.
enemy behavior-
till now there no behavior in Construct for Artificial intelligence, it depends on what type of game you are making, top down, platformer, iso etc. It's easy to make simple AI by checking the distance between the player and the enemy and when player is in certain range of the enemy, the enemy moves towards it.
pause menu-
set timescale to '0' (it is in the "system" actions)
http://sourceforge.net/apps/mediawiki/c ... me_Scaling
EDIT: i think this will help you: