Dogs don't have grudges and you can't take his behaviour personally. You have a difficult rescue dog with issues. He will take a long time to trust you.
He doesn't hate you, he just doesn't know you yet, it can take years before an abused dog trusts you but honestly it is SO worth the tears and the frustrations.
I;d probably teach him to be happy in a large crate so that I could pop him in there with a stuffed kong if need be.
The hand feeding is an interesting dilemma. I stopped hand feedingour feral dog and he came round on his own. However I hadn't got any expectations, if he growled and barked at me I didn't take it personally, mainly because I had other dogs and he was extra so not the entire focus of my attention. I still think I'd go with the hand feeding everything, nothing in his bowl but some stuff in kongs etc.
He probably owuldn't jump a dog gate---although I have had dogs who do. Asda sell them
Teach him to wear a muzzle and be comfy in it, put treats in it to get him used to it and if you use the plastic covered lurcher ones form countrymun they should fit and you can treat him through them. That way you will feel safe when you are out with him.
You can tell people that it is to stop him eating rubbish.

Cheer up, you are doing a great job with a damaged and insecure dog.

rune

Thank you for your responses, especially Rune! I'd go mental without this forum, trying to talk to friends and family about Riley isn't productive generally.

I may have been a tad emotional claiming my dog hates me, I don't always personify animals I swear!

We have been doing one-to-one training once a week but I had a 'shop around' before and have someone coming for an assessment on Tuesday - I think this might lead us down a more productive path, or at the very least I hope.

I managed to catch the postman this morning and I apologized for any 'distress' - I told him at the weekend we would get a box for outside or a letter box guard.

I also left Riley in the kitchen with his bed, some new cushions he could put in or out, every shape and size kong the pet shop sold filled with a variety of meats.

I'm feeling very positive and excited for Tuesday!