As for you self mining BTC directly with your node, that was disable long long ago.
generatetoaddress works fine for me.
You wise guy, please explain to me how I can get coins on testnet if I don't want to claim faucets or if someone sends me coins for free.
It's very hard otherwise, implying that you're going to solo-mine some. Difficulty is about 67 million, as of block 2,378,483. Why don't you want to earn some for free? That's what testnet is all about. I run a faucet, don't hesitate to ask for some:
https://bitcointalk.org/index.php?topic=5359454.msg57912622#msg57912622