Is it normal to still be tired even after sleeping alot?

You can like get more tired from sleeping too much like it's having like the opposite effect on you like backwards sleepings.

It's normal. But if you want to get rid of that, drink a glass of water when you woke up. Psychologically stated that if you're still tired after your complete sleep, you must be dehydrated. So yes, just drink. Hope it helps.

Yes - I get sleepier and tired the more I sleep. When I'm busy I just kind of keep going because I have to - so it's great to be able to crash when its all over. If you're sleeping, you must be tired - so just go with the flow and go to bed when you're tired and sleep. Don't stay up trying to fight it.

Non24???

Most people, according to what I've read, do just fine on 6 to 8 hours of sleep a night, depending on the amount of physical exertion that day. A sedentary person like a secretary, won't need as much sleep as an athlete, for instance.
As mentioned above, too much sleep is not necessarily good for you.

Irregular breathing? CPAP?

Yes, it's normal. Sometimes you'd be more tired than you were before. You should reduce your time of sleeping.