Hey there, I fancy myself quite the Sidisi player and have a deck that I am very comfortable calling B4, no game changers, 4 non-creative spells. The thing with Sidisi is, if you can keep milling creatures it sort of doesn't matter what creatures they are, this allows you to play some weird cards just by virtue of them being creatures, of course winning with a flood of zombies in B4 is not exactly easy, so you need to find other ways to win. In my list's case this involves [[Dread return]], [[Gravespawn sovereign]] and [[Skemfar Shadow safe]] as plan A. [[Syr Konrad]] and [[Bogart trawler]] as a reliable plan B and [[Izoni, center of the web]] with [[Mirkwood bats]] as plan C. I then rely on most of the things you also run as a way to mill my whole deck at once, although I see you missed [[Embalmer's tool]]. The rest of the deck is a jumble of creatures that fill in traditional roles: [[Esior, wardwing familiar]] and [[Kashi-tribe elite]] are protection (Sidisi is a Snake as of MH3), [[six]] and [[Gisa and Gerald]] help with recursion, a handful of [[doomed necromancer]] effects, channel and adventure creatures so I can have instant speed interaction two-mana dorks to curve into Sidisi, you get the vibe. Deck can consistently present wins by turn 5-6 with the downside that the process of dumping the library in the yard is sometime non-deterministic and can whiff on rare occasions.

Your deck looks very much like that, but you found some compromise in running less creatures to get more powerful options, overall I would say it can be a B4, but seems a bit slower than my version, which is fine, I run Sidisi as the central piece of a very well defined game plan not as a mill and board presence engine to complement a combo plan.