I agree with Judaspriester cutting
Swiftfoot Boots/
Lightning Greaves doesn´t seem like a good idea. You need some protection for Muldrotha, since she´s vital for your gameplan. Thus, I would´nt cut
Sylvan Safekeeper either. He saved my a** many times in my Mazirek-Deck, but there he serves, besides the protection, as an additional Sac-Outlet, so maybe he´s not that useful in this specific deck...I´m not sure. :
XSame with
Elixir of Immortality, it seem´s much better than
Feldon's Cane. Maybe go with both, the Elixir and the Timepiece, if there´s enough room?
For bringing back sorceries/instants you could use
Archaeomancer or
Scribe of the Mindful. For my Muldrotha-Deck, I´m considering to don´t play any non-permanents at all, so I could use
Primal Surge +
Laboratory Maniac as an additional WinCon, though I´m still not quite sure about this idea.