Bellowing Tanglewurm might make your creatures unblockable
Thornbite Staff for the little guys
Trailblazer's Boots is great
Ring of Xathrid grows Hapatra and gives her protection through
regenerationHooded Hydra,
Jar of Eyeballs,
Spawning Pit and
Shadows of the Past net you some value back from boardwipes
Citanul hierophants almost works as a second Cryptolith Rites
Decimator of the Provinces is almost as good as a
Craterhoof Behemoth (Emerge can actually bring him out quite sooner)
Sundering Vitae can be free artifact/enchantment removal (convoke, yaay)
And did you
forget about our lord and savior,
Thunderfoot Baloth?
Turning Snakes into weapons of mass destruction:Phyrexian Plaguelord turns snakes into removal/debuff.
Mind Slash can be used to preemptively remove a piece of removal from an opponent's hand. (Henrique used to have it in his Alesha deck and it's quite strong)
Malevolent Awakening turns snakes into recursion
Vampiric Rites allows you to draw some cards.
Primal Growth has excelent value in token decks
Smothering Abomination is quite good if you take some of my sacrifice suggestions.
Things that I didn't like/feel they are useful enoughI'd trade
Rishkar's Expertise for
Shamanic Revelation (better in token-based decks)
Drop
Orochi Eggwatcher and
Orochi Hatchery (flavorful as hell, but too slow. I actually got my Hatchery from you, but I feel like you have to pay 8+ mana for it to be useful since you have to dump 5 mana each time you feel like making tokens...)
Shisato, Whispering Hunter and
Shizuko, Caller of Autumn also seem too risky/not enough payoff
Constant Mists is too situational in my opinion. I'd rather have both
Heroic Intervention and
Wrap in Vigor so that you can save your creatures from boardwipes
Woodlurker Mimic is also very situational
I don't know about
Phyrexian Swarmlord, even with some other infect sources... I feel
Flesh-Eater Imp or
Phyrexian Hydra (or even
Phyrexian Juggernaut) would work better
Cairn Wanderer doesn't get wither/infect, so I don't think there's much point for having him.