If I wanted to sell a larger amount of BTC (e.g. 35) , what would be the best way?
Would an escrow service offer the required security?
Best regards,
W.
Very honestly, the best security you can have for your funds while transacting is by using one of the trusted escrows on Bitcointalk.
Why go on an unknown and fishy escrow website ?
There is a list of recommended bitcointalk escrow services :
https://bitcointalk.org/index.php?topic=2439910.0