Disable / enable an irule via an irule

it is quite difficult to understand what you are trying to achieve without understanding what irules are attached to what vips and their functionality.

I think the following may help:

1. iRules have a "return" command - which allows to exit the current event and not proceed any further -you can use it after some condition checking: https://devcentral.f5.com/wiki/iRules.return.ashx

    

2. "event" command allows you to enable/disable processing of specific event further down the stack: https://devcentral.f5.com/wiki/iRules.event.ashx