Tybis started using grenades waaay to late. Didn't see ant up tilts either.
Against Hero, and most players in general, grenades are invaluable. Don't hesitate to grenade>shield when you're about to get under pressure; if you use it smartly, defensive grenades will win you games.
Most of Snake's vBrawl tricks still apply too, so I'd say you should first check out all his old tricks first.
Some Minus-specific things;
Fair is jump cancelable after Snake kicks. Dair and Nair can cancel into upB after the first two hits. These are pretty important for combos, and can even lead into C4 in certain situations. Also, on Yoshi's Story (Melee), Snake can neutral-toss grenades perfectly onto the lower platforms. This is REALLY GOOD since your opponent is often on the ground level, and will have to jump to grab the grenade. It also lets you edgeguard much more effectively.
Since Fair is JC and the sourspot hits upward, it's possible to - Fair>JC>Fair>UpB>Fair/Uair - to the top blastline.
Example.
I never find Dsmash very useful at all to be honest. It's VERY situational. If you use it wrong, it can hinder you more than help, use it sparingly.
Mortar Usmash on the other hand is very useful when edgeguarding. When you're not using it there, you can charge it a little and then try pulling out another trap while the mortars protect you during your endlag. If you make really good predictions, you can poke people through platforms with it easily.