If you talk about Pug, then think twice. This breed are very vunerable to over-heating. As you know, the mouth of this dog is very flat and as a result they find it difficult to breathe in hot climates. You can confirm this with any other expert. Unless, you can offer an air conditioned environment to your dog, I wouldn't suggest to go for Pug.
Do you know English Bull dog is among the least healthiest dog breeds in the world? You don't want to spend fortune in vet bills, do you? This breed doesn't live very long. They are not very trainable. However, they getalong with kids. But considering so many disadvantages, this is no good, is it?
As long as leaving the dog alone is concerned, this habbit should be inculcated through gradual training. If you impose this straight away, then this may cause separation anxiety to the dog. If you want to leave the dog alone daily for that time then Lab is not the breed for you because they need someone to please. They are very vunerable to separation anxiety. I thing boxer do well in this senario, they are happy left along but make sure this is done through gradual training.