"Well Ackually"
That's expertise in at least 2 skills and 2 tools and proficiency in 4-5 other skills according to your post. So you are looking at multiple feats and classes and DM help according to your post.
What are you talking about? I literally wrote down the build. What other classes? Monk? I left that off for a reason. Multiple feats? I took one feat.
Here is the break down again, more streamlined.
Variant Human Rogue 2
V. Human gives +1 skill and a feat. Using the Feat to get Skill Expert Investigation, which also gives that skill Expertise.
Background gives +2 skills, and using it to get Proficiency in Land Vehicles and Air Vehicles (which is practically worthless for any character, but you are insisting that driving these vehicles is vital)
Rogue gives Thieves Tool Proficiency. Expertise DOWNGRADED to give expertise to the Vehicle rules. Yes, this requires DM help, but you are WEAKENING your character to do this, and I only did so because you specifically demanded he was an expert at both. Rogue gives +4 skills.
That is seven skills total, taking: Stealth, Sleight of Hand, History, Perception, "Science", Medicine, Athletics
With this I have:
- An Expert Detective [Expertise in investigation]
- An Ace Pilot [Expertise Air Vehicles which is useless in DnD]
- An Expert Driver [Expertise Land Vehicles which is near useless in DnD]
- A Trained Ninja [Cunning Action, Sneak attack, Stealth, sleight of hand, Athletics and perception]
- A dabbler in multiple sciences and histories [Science skill equivalent to Arcana, history and medicine... which is actually MORE than a dabbler and makes him a trained scientist, archeologist, anthropologist and doctor]
The only thing I'm missing from your list is "one of the 10 best martial artists in the world" Mostly, because that is an arbitrary measurement and will immediately need high level because you claim that other martial artists must be high level, so since he is better than them, he needs to be higher level. But you are going to quickly run into the problem that the more levels of monk you take, the more magical and mystical he becomes.
So... literally I don't need any more feats to cover what you said, and I only need an arbitrary number of MAGICAL class levels to make your ultimate mundane warrior. You conception of broad skills is flawed on two fundamental levels, the first being you don't seem to actually know what is possible. Heck, Rogue 4 (Mastermind) and two levels of monk and I've covered literally almost every single skill. Even if you demand more expertise, if you accept just being a trained pilot and trained driver, then I can make a level 8 batman with 5 skills using expertise, and training in another six.
Level. Eight. And your only real defense currently is to either add to your list OR to argue that I need more monk levels because he needs to be an even better martial artist with more Ki and more magical abilities.