What is Jaggers up to?

First, why does he keep Molly the murderess and Estella's birth mother as his housekeeper? Does she do more than keep his house? Does he have feelings for her similar to Pip's feelings for Estella? Or perhaps she is an exhibit, a trophy from his first big case win?

Then there is an odd exchange between Wemmick and the turnkey at Newgate Prison referring to Pip:

Turnkey: 'Is this young gentleman one of the 'prentices or articled ones of your office?'

Wemmick: '...Well, supposing Mr Pip is one of them?'

Turnkey: 'Why then, he knows what Mr Jaggers is.'

I wondered whether he was hinting Jaggers was gay; however I did not think homosexuality was acknowledged in nineteenth century British fiction. However, when Mr Jaggers invites Pip and his three associates to dinner, he takes a shine to Bentley Drummle. That made me wonder whether Bentley Drummle was an attractive man, something that Pip could not see. However, at a later meeting after the marriage Jaggers says,

"So, Pip! Our friend the Spider has played his cards. He has won the pool.'
It was as much as I could do to assent.
"Hah! He is a promising fellow - in his way - but he may not have it all his own way. The stronger will win in the end, but the stronger has to be found out first. If he should turn to, and beat her --'

After that I wondered whether Jaggers had seen from the first that Estella would marry Drummle. When I discovered on the internet that Drummle had died by the end of the book, I wondered whether there was a second phase to the revenge mission against men and that Jaggers was aware of it. The first phase would be the breaking of hearts that we all knew about. The second phase would be to destroy a man. I wondered how she would do it. Maybe she would drive him to suicide. I found that very depressing because that would mean Estella was a psychopath. However, it did not turn out that way, so maybe Jaggers just approved of the marriage because he did not want Estella to continue her cruelty on any man who was not as unpleasant as Bentley Drummle.

Lastly, what type of lawyer is Mr Jaggers? Is he a solicitor or a barrister? It seems like he argues in court, so that would suggest a barrister, but in his other tasks he seems more like a solicitor.