
Hi
I have French Bulldogs as do close family members , I will try and give you honest answers that reflect our experiences.
1 - It depends on what line your pup has come from really , our dogs will walk all day , never tire and don't have problems with their breathing at all . My sister used to walk her boy but he collapsed ( it wasn't in the heat either ) on a walk once so she is careful and he only gets ten minute walks now.
My mams will also walk all day and is really fit.
Mine love a walk through the woods , most will be able to cope with this IMO. You have to be careful of them jumping when pups as to not do damage to their backs , so no jumping on and off sofas .
2. Mine get to lie in the sun if they want , they are sun worshippers and have never over heated. They will lie in the shade if they want , I always have water available so if they want to cool down and lie in it they can.
3 . Yes they will be able to play , French bulldogs are like bulldozers when playing , they will cope absolutely fine with a JRT , mine play with DDB'S and a Rott .
4. Ours go out in the winter , mine don't wear coats as I think they are fine , my mam has a coat for hers , so it's personal choice, they do like the warmth of the radiators though and will snuggle up if they feel cold. I have some great photo's of mine running round in the snow :)
I hope this helps you a bit , but please do your research before buying , find a reputable breeder , that health tests , they are in demand at the moment and you will come across poorly bred puppy farmed dogs . You may have to be placed on a waiting list so be prepared to wait for the right dog . I waited 5 years for one of mine and it was worth it.