Well for starters, you should probably get a basic model completed first before trying bodygroups and transparent textures.

Bodygroups should be very easy with the new importer, though. There should be a checkbox for what geometry you want to hide for characters (e.g. his gas tank) in the importer. Otherwise, you'll have to do it manually with a QC file.

This might help with transparency: http://gtm.steamproxy.vip/groups/BlenderTutorialCommunity/discussions/0/864974467279350930/

Ask around as well. I'm no longer as active here as I once was.