As it stands, the warlock class's Find Familiar spell is a bit overpowered. While I love how much flexibility being able to summon an imp gives, it needs to be reined in. Here are three points about the imp:
1. Scouting potential: Currently there is no discernable limit to how far an imp can travel from its caster, which is a bit of an issue. While it's great that an imp can be used as a scout, the mobility afforded by its flight and the ability to turn invisible means no end to fun but ridiculous cheese strats where you can send your imp to find the nearest waypoint. I'd suggest limiting how far the imp can move from the summoner or at least limiting the information that the imp relays to the caster.
2. The imp in combat: The imp is able to act independently of the caster which practically gives a warlock multiattack. Furthermore, enemies never seem to attack the imp and just let it float around and take attacks of opportunity.
3. In addition to these advantages, the makes independent skill checks. I don't mind this part, but it should just be considered for balance.
4. Lack of darkvision: This is actually a nitpicking suggestion for a buff, but I would suggest giving the imp darkvision as it has in the 5e Monster Manual. The inability for my little demon friend to see in the dark is silly.
Case in point, I adore the imp but it's way too abuseable for now.
