I am not the person who create that plugin but I am doing whatever I want with it so I can maybe answer your question.
1. Can i use YAR in my situation?
Answer: Yes, I don't see how this will get in conflict with SimpleFollow.
2. Do i have to put lower movement speed on main bot, account (main+3follower) but all on bots.
Answer: No, the follower will follow your leader and fight any monster that get in range on them. So does not matter in any situation I know.
3. The 4 bots are running in 1 computer. Can u tell me how to configure this plugin:
http://scr.hu/0ijg/bybqc on main account and 3x followers. Witch option to check?
Answer: On the same computer you keep the setting I you show in your screenshot and change localhost on all your bot for your local IP address. EX. 192.168.1.100
4.
http://scr.hu/0ijg/y1y2t im using this from the thread.
Answer: Use the latest plugin publish in this thread. It will offer the best performance.
5. The biggest problem atm is: [...] kill boss guardian.
Answer: Configure properly each Trinity on every bot. There is no other way around all your current issue related to each individual bot behavior.
6. I have to uncheck the questtools? i just load profile: adventurer/nephalm/greater.
Answer: NO NO... on your follower you just need 2 plugin enable to make it viable. Trinity and Questtools.
Questtools is the most important one.
I make a little adaptation to the current SimpleFollow version by removing the action from the follower to always teleport himself to the act 5
and also remove the action of the follower to make a Grift.