Depends on the facing/height of the unit so you’ll have to view and check on site if that’s a concern for you. I’ve only seen a small plot at a distance from another owner’s unit at level 20+ facing away from Jalan Cheras.

For the specific unit E block studio under discussion, I’m not aware of any cemeteries facing it, though don’t take my word for it and best to verify in person.

Yes, there had been floods in the past but it has tended to occur around the MRT station and as far as I’m aware, it subsides quite quickly. Maybe someone else who has better insight to this can comment. I’m not too familiar with how the drainage works but I haven’t seen any cases (from owners’ WhatsApp group) where there was severe flooding in the underground parking spaces.