Question about parallel flows and interruptable activities

I have a small activity diagram here and I’d like to ask you whether this is correct UML and also whether the semantics are correct (The intended semantics should be obvious, otherwise feel free to ask)

My main problems here are:

  • If the escort is destroyed before all enemies are gone, will the corresponding event interupt the other waiting event.
  • Should there be a flow arrow to the interrupting event or are interrupting events in interuptable activity sections always just sitting there
  • If just sitting there, when exactly does the interupting event node start to listen / become active? once the interruptable section is entered anywhere? does it then become inactive once the section is left?
  • Is the parallel flow from the Intro Dialogue node on correct? Do I need all those forks and joins or can I ommit some or am I even missing something here?

This is really a special case which is not clear to be reading UML literature and I’d like to be sure I’m understanding the standard here.

Thanks in advance

http://media.wcsaga.net/keldorkatarn/simple_flow.png

I think adding decision nodes will clarify some things. I assume you want the flow to differ depending on whether the escort or the enemy is destroyed first.