1.Stats: Should Girafarig get a stat boost, Evolution, Mega Evolution or nothing?
Girafarig is a pretty terrible Pokémon. As one of the rejected designs for Gen I that made into Gen II, it didn't have much chance to be great, but in the first generation it was introduced, it was a mid-game Normal-type that served as a gimmick mon. In the third generation, it was a Safari Zone species, and in DPPt, it returned as a mid-game Pokémon that was more early mid-game. That was sadly its height, as it returned as a post-game species in B2W2, and as a late mid-game species in ORAS.
Girafarig stats are comparable to a powerful middle evolution, and it is weaker than its de-facto counterpart, Stantler, which has 10 more BST. 10 more BST is good enough for it to be not cripplingly terrible, but it is obviously not enough.
What Girafarig truly needs is either a +50 BST upgrade, or an evolution with +80 BST. A Mega cannot work without an exclusive broken ability, and a small update cannot work, though it is still necessary to match to Stantler.
2.Should Girafarig get more abilities?
Girafarig has a full set of abilities, but its first two abilities are terrible, and its HA is focused on its weaker Attack.
Thematically, better abilities it can get would be Shadow Tag, Strong Jaw, Trace, Magic Bounce, Magic Guard Psychic Surge and Speed Boost, but other abilities like Keen Eye, Illuminate, Frisk, Forewarn, Magician, Synchronize, and Intimidate.
3. Should Girafarig get more moves?
Yes. Most obviously Girafarig needs something to use for its large Physical movepool like Swords Dance. Outside of that, Elemental Fangs, Poison Fang, Tri Attack, Aqua Tail, Elemental Beams and their upgrades, Wild Charge, Dark Pulse, Flash Cannon, Power Gem, Jump Kick and Hex would be all fitting moves.
Slack Off and Megahorn would be fun as well, so would Iron Head and Head Smash. And of course Boomburst for the lulz.
4.What additional typing Girafarig can have?
Dark is the most obvious one, but outside of that Electric also fitting. Grass and Ghost can also work as well.