I don't know his story, but I had a little chuckle at the juxtaposition of "quite good at opsec" with "in federal custody"
You can be good and yet the heavy hand of the law still gets you. They got Escobar and "El Chapo" Guzmán too. And his operation was smaller than either of those fine gentlemen's.
One probably has to be perfect - not just good with opsec - to maintain anonymity from the government. The FBI has multiple side-channels, such as agents physically tracking if you're home at your "super-secure" 7-VPN computer when your Internet persona is active online
You can be perfect 999 times and still get fucked by that 1 mistake.
999 people can have a little opsec error and 1 person can still have perfect opsec.
He created truecrypt for his, well buisness. But are there any other indications, he also did anything towards cryptocoins? This is the first time I heard of this theory and so far I really doubt it. Satoshi seems to have been one tinkering alone and in peace with his concepts. Le Roux seems to have been more involved in action, too busy to create bitcoin.
Aside from his background as someone actively promoting encryption, Satoshi stopped posting just before Le Roux was arrested.