Quote: "Right now transferring characters from SL to GG looks like another complicated situation, and maybe I'd be better off with Fuse or something"
Well..If u looking 4 somethink that allows u to make SL or any else characters GG ready with just one mouse click u will be dissapointed 4 sure.
That process i showed u is absoloutly not complicated, except the part with fragmo rigging but its not neccesary until u want standart GG animations on r characters.The way i desricbed above will be took about 2-3 minutes to turn a model into GG.As GG doesnt support xmf files i proposed u 2 use blender just 4 import and export the model, u dont even need 2 be familar with it just follow the instructions from the videos.
Quote: "The SL rigging system is beyond complicated, with around 500 bones/helpers"
Its not possible 2 export a raw unrigged mesh?However by importing it 2 blender u could just remove the bone, and rigg it all over again in mixamo.
Quote: " can you (or anybody else!) suggest the simplest, cheapest way to customize attractive characters in another program, then import them into GG, hopefully rigged and with animations?"
U can look 4 gameready characters on turbosquid, cgtrader......
Take a look on Pyrate Mykes MakeHuman2GG tutorial, MH is a free software where u can create characters
Heres a example of models from there used in GG