You are to be commended for the effort you put into that application. One of the problems with may visa agents is that they are in it for the money, they don’t actually care about their clients. I’ve helped many friends apply for various visas and I put the kind of effort, care and attention into it as if I was applying for myself.
Got lucky I guess. But the application was like writing War and Peace, maybe they got bored reading it. On a separate occasion, in 2007, I applied in the UK for permanent residency in Australia. I obviously fulfilled the criteria, and having submitted a box file full of paperwork, in person, to the Aussie Embassy in the Strand, I was granted my permanent residency within 24 hours!
I helped a friend and his Thai girlfriend apply for one a couple of years ago and it was granted in less than a month, so obviously there are variations in timescales.
Basically, yes. In Australia they have a term 'de facto' which unlike the UK 'common law', is a legal status, so you can apply for what is called a partner visa, even if you are not actually married, but are in a provable 'de facto' relationship. The United Kingdom does not recognise common law marriage. That said, the rules in the UK may have changed, I've been out of that loop for some years, but I do believe they have a legal partnership status now. There was certainly a point in time, back in the 90's, when if you were in a hetrosexual relationship and you could get married, i.e. you were not barred from doing so because you were already married, then to get residence status for your partner, you had to marry. I know that because it happened to me. The irony was that if you were already married, but not divorced, or you were in a same sex relationship, so in both cases you could not get married, then you could apply for residential status for your partner. This was before the The Marriage (Same Sex Couples) Act of 2013 came into force in the UK in March 2014.
I did one for a friend of mine and his partner a couple of years ago. I live in Thailand, as did they, so the application was submitted from here. I believe the cost was about AU$ 7900 with no agents fees, as I did it. If you can work your way around the bureaucracy, and the not user friendly online application, it’s doable yourself.