Only real feedback I have is that you probably should put in more 2 mana ramp. I'd cut whatever cards turn out to be underwhelming in playtesting. Otherwise the deck looks pretty beastly now.

LoneCrusader399 Why 2? Not saying it's a bad idea, I just want to know the context you're coming from.

Fellwar Stone and the signets specifically. I've always found 2 mana ramp to be both the most efficient and best at keeping your options open to play other spells when drawn in later turns. I know this is more of a theme deck but having more early turn plays will increase your chances of winning as well.

Also, if you want more ways to get Serra's Sanctum you should consider Expedition Map as well.

I havn't had many mana issues as of late, but I'll keep it in mind and monitor it.