How to remap graph properties?

Slightly more cumbersome alternative to your sp (hopefully little less tedious to use):

ClearAll[mapF]
mapF[pr1_ -> pr2_][g_] := SetProperty[g, 
   pr1 -> Cases[Options@g, Rule[a_, {___, Rule[pr2, v_], ___}] :> Rule[a, v], Infinity]];

mapF[r : (_ -> _) ..][g_] := Fold[mapF[#2][#] &, g, {r}];

g3 = g // mapF[VertexLabels -> "name"]

g4 = g // mapF[VertexLabels -> "name", EdgeWeight -> "weight", VertexSize -> "Faction"]; 

PropertyValue[{g4, #}, VertexLabels] & /@ VertexList[g4]

PropertyValue[g4, EdgeWeight]

{"4", "5", "3", "3", "3", "3", "2", "2", "2", "3", "1", "3", "2", "2", "2", "2", "6", "3", "4", "5", "1", "2", "2", "2", "3", "4", "5", "1", "3", "2", "2", "2", "3", "3", "3", "2", "3", "5", "3", "3", "3", "3", "3", "4", "2", "3", "3", "2", "3", "4", "1", "2", "1", "3", "1", "2", "3", "5", "4", "3", "5", "4", "2", "3", "2", "7", "4", "2", "4", "2", "2", "4", "2", "3", "3", "4", "4", "5"}

Note: the values of weight are strings.

With IGraph/M, we can transfer the value of one property into another one. For example, to copy the "weight" values into EdgeWeight, use

IGEdgeMap[Identity, EdgeWeight -> IGEdgeProp["weight"], g]

This does not remove "weight". It only copies its values into another property.

There is also an operator form for these functions, to allow chaining:

g // IGEdgeMap[#&, EdgeWeight -> IGEdgeProp["weight"]] // IGVertexMap[#&, VertexLabels -> IGVertexProp["name"]]