I feel like Hypno without Rest kind of ruins Hypno as a possible Zam/Chansey replacement. Letting Lax and Tauros have free turns is poo, but you can't really go without healing on Hypno, and you can't really run Reflect because you need all of Twave, SToss, and Psychic. Twave may conflict with Venusaur, but combined with SToss you easily paralyze SubZam for Venusaur.
Golem is cool, and paralyzed stallers fear him. Reflect is often foregone for Substitute, so that really only helps the turtle boulder's case.
Venusaur is interesting, and a move I approve of in Stadium with Gengar usage way down due to Sleep being nerfed to hell and Zam being uber-popular with the advent of Substitute. That being said, Victreebel might be better; you get better Attacking stats and, while you lose Speed, you don't really lose the ability to outpace anything relevant (except for Cloyster and other Victreebel, which are marginally relevant at best). One thing to watch out for, though: Psychic Slowbro. After an Amnesia that shit can OHKO.
Raichu is poo, but I will grant you do have Rock problems without Egg. Still, Raichu doesn't really solve that. Jolteon is nice with Focus Energy, but has a bear of a time with just giving those guys free switches, so I'd advise against it in this slot. For something gimmicky here, Zapdos with Reflect + Rest can actually outlast Golem, or at the very least get it to consider bothering with Rock Slide as you switch out to Slowbro, Venu/Vic, or even your own Golem. Or, for something more conventional, you could ditch the Electric for something like Snorlax who can draw Rocks in and whittle them away with Earthquake (or actually catch them by surprise with Surf, something Raichu can't really do). You don't really need an Electric for Slowbro, since you have the Razor Leafer to beat it and your own Slowbro to stall it out should it come to that.
Slowbro is kind of defining Stadium at the moment since lots of Chanseys are ditching Tbolt, Zam is amok, Sleep no longer checks him, and Hyper Beam isn't used nearly as much and therefore can't finish it off. Gengar and Starmie can easily be Twaved and put into peril the next time they try to ruin you.
Tauros is a nice crit machine, but Hyper Beam is really really bad in Stadium. It's strong and it can get you KOs, but misses are the worst and you give up the next turn to something that'll probably just end up killing Tauros back (unless it's late-game, in which case you've probably already won without Hyper Beam). I don't know what would be best for a fourth move, but I feel like Hyper Beam might easily be better replaced by Substitute, Double-Edge, or even Stomp.