I would like to use blocktrail but I have become way too used to blockchain.info's nice layout... I would like that they fix the onion url those because I always get those annoying "out of quota" or something errors.
Stop using onion's address for browsing blockchain.info and accessing its wallet. In this way your wallet identifier will get traced by one of the exit nodes. Then they will start their own brute-forcing to get back into your account.
Money. I don't think Blocktrail gives a shit to what Bitmain does with it now, I am sure they all made a nice profit.
No. Blockchain is a free and independent explorer and they didn't have any profit whatsoever in those years.
That's why "maybe" they are either leasing out their brand to Bitmain for some yearly income or sold them directly for a large sum.
Upcoming years will reveal what the actual intention was. As I know very well, they (Bitmain) already had their own blockchain previously.