I would like to make a perk that increases accuracy but I don't know how to do this. I've looked at other accuracy perks but they only increase accuracy in VAT. Same with the run n' gun perk I don't get what it says, which of the many values only affect the 1h weaps?. Any help?

For non-VATS accuracy you reduce Gun Spread (look at Trigger Discipline). So if you want to improve accuracy across the board you should increase chance-to-hit (for VATS) and reduce gun spread (for non-VATS).