Whenever you can, always level up both Locksmith AND Hacker until Tier 3.Tier 3 Hacker requires you to be level 21) Also perk tiers require a specific generic level as well as a perk requirement.I will recommend as well as note perks that you're going to need to complete all achievements in Fallout 4.SPECIALs currently can exceed 10 with the use of perks and bobbleheads.
Plus being a higher level generally equates to easier game-play.
The more intelligence you have, the more experience points you receive which will ultimately help you obtain level 50 at a much earlier rate (less grinding).