"1. How often do you bath a dog ? And what sort of dog shampoo do you use"
With the breeds they use...if they get too dirty to brush it off, then I'd give them a bath, any dog shampoo really, it's not likely to be more than once or twice a year really.
"2. Do you clip the claws like trim them or just leave them?"
Depends on the dog, some wear them down enough just walking, some don't and they need clipped.
"3. Do you brush the teeth twice a day and what do you use ?"
Nope, once a day is the ideal, but I manage every few tbh, dog enzyme toothpaste and a brush
"4.if all four of us are in the car, where does the dog go?
In the footwell of the back or in the boot?!
Surely not the boot?
But DH wants me to ask!
or on the middle seat of the back of the car
And do we need to tie its lead to somewhere or something ?"
Crated in the boot is safest, then with a guard if you can't fit a crate.
Or on a seat with a crash tested harness, but there are only a couple of those on the market.
If you crash with a loose dog in the car, it will be thrown about, which obviously is an issue for the dog, but also passengers being hit by the dog.
"5.If we get a 8 week old puppy
What will it be able to do toilet wise ?"
You won't, they put them out to puppy walkers at 6-7 weeks and...it will not be housetrained or anywhere near being.
"6. Will it destroy us having to let go?
When it's time to leave ?"
Probably
"7. How many hours will a puppy sleep for ?"
They do about an hour and a half asleep and then 45 minutes of havoc and repeat all day.
"8. How long can I take it out on walks?
Will one or two hours be too long for the dog!"
You can't walk a puppy that age at all, they'll be fully vaccinated by 12 or 14 weeks (depending on the vaccines used) until then, they need to be carried off the ground anywhere that other dogs may have been, after that it's 5 minutes per month of age until 18 months... but you'd no longer have it by then anyway.
"9. Do you think males or females are better?
And why?"
Makes no difference you'll not be able to pick.
"10. Would it be a good idea put out stair gates up ?"
Depends on the layout of your house, I just use my doors.