Should I buy a condo that has water damage on the ceiling?

Hi. My husband is retiring and we need to downsize from our home. I found a condo in Wasaga Beach that has great bones and think I can get it for a very good price. But it smells of mold and has water damage and discolouring all over the ceiling, the walls are cracked, the laminate floors scratched, the kitchen falling apart, doors need replacing. It hasn't been lived in for a while.

Also, I looked at an identical apartment in the building beside it. It has water damage in the exact same place on the ceiling. So I think it is a structural problem in the roof. Both apartments are on the top floor of a three story building.

Basically I am afraid we may need to gut it to clean up the mold and start from scratch. But how do I know? I am highly allergic to mold so this really scares me, but it could turn out to be a beautiful nice sized, bright apartment with a great view if only I can be assured it will be completely clean, and that I can afford to do the reno. It is 1150 sq. ft. with a kitchen that is 14' by 8' and I have about $40K to work with. I want to put hardwood floors in, a new gas fireplace, five new appliances, new kitchen cabinets and counters, and maybe redo the two bathrooms. Thinking of an Ikea kitchen and doing what I can myself. Can this be done?

The other thing is that I am very allergic to cigarette smoke as well and worry that it might drift up from the floor below us. Can extra insulation help or is this not something you can control. I haven't lived in an apartment since I was young, and I did get sick there.

Thanks for any advice.