Feels like this only works if your bosses (your spouse and employer) are willing to acknowledge the realities of WFH with a baby. Otherwise, forget it.
The first six months are by far the most difficult. Once you can get the baby on a consistent sleep schedule, you can start to plan around that. Granted, you won't have time for much else in the world but you also won't be at risk of being fired.
The real crime here is that maternity/paternity leave is far too short and it seems that most employers simply look the other way for the first year in observance of that fact.
Depends on the kid. Mine was a superstar sleeper from 2-6mo (8p-7a every night, predictable 90min-2h naps during the day), and then as he got older his napping took a nosedive -- shorter duration, lower quality, less predictable.