Openrails induce delay and get signal state

[KaPri]

Hi,
I am new to openrails. I have few questions about openrails. I hope the community members would guide me on this.

1. How to change the state of signal from approach to proceed to forward other than through dispatching window ? Could any one please point me to the location where the change of signal state happens?
2. I am planning to induce delay to trains dynamically. How can i do that? Is it possible to induce delay in AI driven trains ? I am thinking of change in timetable, am i in the right direction?
3. Can we create multiple AI trains and run all of them simultaneously in the network ?

Basically, I need to create a network with multiple AI trains and their speed, time of arrival should be updated dynamically (induce delay). I should have control over the signal state too along with the information of trains running along the track. I am trying to simulate deadlock situation where the signal should decide which train should it let pass. Request you to provide me with the information or guide me to acheive this scenario.

Thanks.