https://www.dndbeyond.com/characters/subclasses/58803-smuggler

Is this class viable and balanced?

I plan on making a "face" sort of character as a rogue. - I need to smuggle and help players/the group around as a sort of guide with this character.

Honestly seems fine to me.  But if you want to be a Charisma-based rogue, may I suggest Mastermind?

Mastermind seemed very weak in a scenario where combat may happen often, in such a way I fear it will not matter too much. 

I think this hits my character in rp more than mastermind does :) 

This seems like it would work phenomenally. A very good fit for a smuggler guide of sorts having abilities that are very viable in combat, while also being a good mix of Dexterity and Charisma focuses. 
Plus if it works better for the characters rp more than other variants such as the mastermind, that right there is a massive go ahead! 

Yeah, Mastermind is more role-play-oriented than most rogue archetypes.  This one is pretty cool.

The Smuggler has some design issues.

Nothing To See Here: Hiding objects using a Dexterity (Stealth) check doesn't make much sense; that's what a Sleight of Hand is for, and that's also exactly what the Thief's Fast Hand does. Letting another creature hide using your Dexterity (Stealth) roll is really abusable and doesn't make narrative sense. Yeah, I get that the idea is that the smuggler is helping someone hide, but there's already rules for helping someone on ability checks and they merely grant advantage. A clumsy, heavy armor fighter shouldn't be able to hide using your +10 Stealth roll. But even granting advantage might be a bit much. Letting a creature hide without them having to use an action is already really strong.

Low Profile Leader is ridiculously broken. It's kinda like being able to cast Pass Without Trace at will, except your friends don't have to stay within 30 feet of you after they make their roll.

The way Superior Preparation shields the whole party  from the consequences of being surprised is also ridiculously strong. It's also lacking a side use for when those situations don't come up.

If you ask me, Razor Wit and Magical Appraiser's Eye are the only two features that really hit that sweet spot of useful, non-disruptive, and flavorful. Overall, the subclass has some glaring flaws, and if I were DMing, I'd prefer that you just picked Thief or Mastermind and made "smuggler" your background.

Speaking of which, Mastermind has some great combat synergy with a lot of classes. Giving someone advantage on an attack as a bonus action is great for:

• Any character with Sharpshooter or Great Weapon Master.
• Rogues, Paladins and Warlocks with Eldritch Smite. Advantage = more crits = big Smite/Sneak Attack damage. Bonus points if they have the Elven Accuracy feat.
• Spellcasters with attack roll spells (e.g. cantrips, Guiding Bolt, Chaos Bolt, Inflict Wounds, Vampiric Touch.)

There's probably at least one person in your party that would benefit from being given advantage frequently.

I agree that at the beginning, Mastermind rogues are decent at combat, but they get Master of Tactics at 3rd, Misdirection at 13th, and no Combat ability at 17th, so I feel like it can help in combat, and definitely adds to that strategist type of character, but they seem to be mostly roleplay oriented.