Whether he's a good dad or not - and as you rightly say we don't know him - is irrelevant to the current issue
You're not going to get ANYWHERE trying to tackle him while he's pissed!
To be perfectly honest it sounds like he is an alcoholic and you need to accept that.
Accepting that ALSO means accepting there's actually nothing you can do about it!
I know that's not what you want to hear but it's true
My father, grandfather, my dads siblings, cousins (children of those siblings), great uncles/aunts all addicts, mainly alcoholism, but often other addictions too.
For YOUR sake you really need to learn the following:
You didn't cause it
You can't control it
You can't cure it
The ONLY person who can is him and ONLY if and when he really wants to.
Contact al-anon or similar and get support for you, recommend the same to siblings.
Does he live alone? Are there potential safety issues with him possibly falling, leaving hob on etc?
If so do all you can to remedy that.
But you can't actually just tell him you're worried and he has to stop and that will work.
Sister is his sponsor, thats really not advisable!
A sponsor should be someone without a complicating previous relationship with the addict.
He shouldn't be providing childcare for anyone to be honest.
Dad would never drink when in charge of the children addicts don't regulate themselves the way others do.
Does he drive? As pp said chances are if he drinks of an evening he's likely still over the limit WELL into the next day, not just the morning. He shouldn't be driving.
He won't be fit and healthy either - he might APPEAR to be, the addicts in my family appeared to be at times mainly as they were avoiding the dr like the plague! Also because they're drinking rather than eating and so tend to be very slim...
Until the effects catch up with them and then they can end up bloated and otherwise obviously ill.
Contrary to media portrayals etc they can go years, even decades before the effects show.
My dad and grandad were both army, passes all their fitness tests, then 10, 20 years after retiring the jaundice, bloating, poor blood vessels, ruddy face etc becomes more visible and the internal effects brought it all home to roost.
My dad is now bedbound and can barely sit, he's in constant severe pain.
Again contrary to media portrayals etc his liver is fine...his heart, brain, kidneys, bladder, pancreas, throat, stomach, bowel... are not!
Alcohol from a physical/Medical perspective rots the organs, breaks them down slowly but surely.
Retirement is often the catalyst for alcoholism to rapidly advance. yep!
You're at the bottom of a dysfunctional pile here
Totally agree
Also agree the rose tinted specs need to go!