A permanent's controller is whoever put it into play unless the spell or ability that put the permanent into play states otherwise.

A player can gain control of a creature with Auras and Equipment attached to it; an Aura's or Equipment's controller is separate from that creature's controller (C.R. 303.4e, 301.5d). Once that happens, however, as a state-based action, each Aura attached to the creature may or may not remain attached to it depending on what the Aura can enchant; for example, in general, Auras that say "enchant creature" (e.g., Crab Umbra) will stay, but Auras that say "enchant creature you control" will go to the graveyard as a state-based action if the Aura's controller is not the same as the creature's (C.R. 704.5m, 303.4, 109.5).

Loxodon Warhammer gives the equipped creature lifelink, among other things, so that if that creature deals damage, that creature's controller (not necessarily the player who controls Loxodon Warhammer) gains that much life.

Totem armor on an Aura works the same way no matter who controls that Aura. In general, if a permanent is enchanted by two or more permanents with totem armor and would be destroyed, that permanent's controller (not necessarily the controller of any of the Auras) chooses which Aura's totem armor effect to apply (C.R. 616.1, 616.1e).