1. Sorry but if btce have all amount of some crypto or more than 55% and return to any user only 55% in that currency that is STEALING for sure. Btce you can't play Robin Hood - take from those who have and give those who have not. If someone would consider trying to retreive their NMC for example from US, they for sure will not give back any NMC if they didn't seize any of NMC (they could seize only fiat and ethereum for example).
The only way you can go to be fair is announce percentage of each crypto and fiat separately and give back exactly that percentage to each user and do this for each crypto/fiat separately. Only then you can give back rest calculated from each crypto separately in new token.

2. Is BTE bytecoin or some other not yet announced coin? If it is bytecoin then its worth nothing in comparison to 1USD:
https://coinmarketcap.com/currencies/bytecoin-bte/
if it is some new coin then it will probably be worth nothing as soon as market takes into concideration the debt.

3. What is the mysterious investing company??? All will be obligated to give away their identities to some unknown company or to btce who is charged as far as we know for identity theft. It's another scammish point - if someone agreed to your anonymous regulations and deposited you some crypto you can not require his documents especially if no fiat is returned. You can require only from new customers or after money is returned.