Yes to the first - they've negotiated with kobolds before, but they tend to attack pre-emptively when they smell a fight.Do you use reaction rolls and morale?
No to the latter - I've tried to used common sense, but mostly the fights have been over before anyone realised they were in danger. I'd let them keep low intelligence monsters at bay with flaming torches, if they thought of trying it.
I do, but the players have yet to run from a fightDo you play that monsters can sometimes be distracted from pursuit by dropping food or treasure (depending on the monster's intelligence)?
I need to get them to recalibrate their paranoia though. They came across a really obvious trap and set it off to see what it did (amazingly they survived the fireball). Yet they nearly bypassed a treasure hoard because it might be a trap