I've got secondhand embarrassment reading this, please don't flirt with tradesmen for free decking!
I've read the whole post and see why he might not be interested in maintaining OP's home, despite having the time and money.
OP I felt really sad for you reading what a cunt he was towards you when you needed his help and had a bad back. The way he talks to you, the things he says, his actions remind me of one of my least healthy relationships. He isn't showing you kindness and warmth, he wants to wrong foot you and be right. He wants you to be quiet, he told you that. If he was dating your friend or daughter/sister etc, what would you think if they had told you this?
Being single is better than putting up with this useless lump. You're a team player, he's not. He's selfish, miserable, grumpy and quick to turn a conversation into an argument, he's not conflict avoiding, he's creating it.
I hope you see things clearly and it sounds like a blessing that you didn't buy your house together. Get him off the tenancy. The longer he's in your house the more complicated it might be getting rid of him. He might try and claim rights to your home.
There's kind, loving men out there who are generous with their time and show they care with actions and words, you deserve that.