ESA - Various Questions require answers please

Trying to help someone in need of information regarding ESA and I said I will try my best to help, so here goes.

The person is nearly 50 years old and been very very long term Sick and been on benefits most of their life now, He lives with his father in his fathers private owned house, his father is a pensioner.

He is in receipt of the enhanced rate PIP (monthly), I don't know if that info helps here but I thought it's best to mention that just now as I am sure it asked for details of that on the ESA application form too.

He was on ESA previous to this reapplication and this is just the stupid idiotic usual yearly ESA application needing done once again , I don't know why they do this as it's as obvious as the nose on your face that the person cannot and won't be able to do any type of work Ever - unless there was some magical miracle cure which has literally zero chance of ever happening.

Anyway, questions,

1. How long do people normally wait in maximum for their result back from the ESA decision team as it's already been about 6 weeks or more that he has waited and no reply as yet ? (he is still being paid ESA as normal though).

2. He currently gets about £224 (plus some pennies) each two weeks in ESA, I have recently heard some stories that some people reapplying for ESA can end up with extra money more than they had before, one that surprised me was someone I know in person who said to me their ESA had went up to £160 per week after their new application, that was a big surprise to me indeed considering the person I am speaking on behalf of just now only gets £224 per Two Weeks which is vastly less money, strange ?

2a. So, is the money changing with ESA or something ? and if so, would the people who have been getting less receive the missing money backdated I wonder ?

I am sure I have more questions but as usual I can't think when I am typing, no doubt the questions will come to me though.

I look forward to anyone's reply.

Kind Regards

Thank you.

thanks @Gordon

Have you ever heard of ESA being as much as 160 per week ? I haven't.