Congrats Yare! Excellent tourny report.

Have you considered the Painter's Servant/Grindstone win condition is:

A. Cool/Fun, at least IMO
B. A nice, cheap (mana and $$ wise) 2 card combo and
C. For multiplayer it's essentially a tapping laser beam, knocking off an opponent of your choice. Since you have to tap the Grindstone it gives the other opponent one more turn, but it seems highly effective.

I can't speak to your specific meta, but ever since I read that Painter Stone combo I've wanted to use it, and a more casual Stax deck seems like the perfect place (can dedicate many slots to this, making the deck more combo-oriented, or just a couple, treating it like any other win condition for Stax).

I have been away from Magic, really in any form, for quite a while. Food Chain Goblins was the only deck I ever played seriously in Vintage (I played all sorts of Stax variants online, but never with physical cards), and as I have the main body of this deck (sans Power) I'm looking to see how I could modernize it to at least have a chance in the modern Vintage environment. I know, for example, that Vexing Shusher looks like a very pretty little card. I won't even bother with the sideboard as it has fallen apart into a largely Casual sideboard and I'm sure the metagame has completely changed what's needed in the board.

6 Mountain
4 Taiga
4 Wooded Foothills
4 Wasteland
1 Strip Mine
1 Sol Ring
1 Mox Ruby
1 Mox Emerald
1 Black Lotus
1 Lotus Petal
4 Food Chain

4 Goblin Lackey
4 Goblin Ringleader
4 Goblin Recruiter
4 Skirk Prospector
4 Goblin Piledriver
3 Goblin Warchief
3 Gempalm Incinerator
2 Siege-Gang Commander
2 Goblin Matron
1 Goblin Sharpshooter
1 Zo-Zu the Punisher (this guy got added just about when I stopped playing, so never really used him)

Any help would be greatly appreciated (obviously, along with MD modernization I need at least a generic board).