She is not much more than a newborn (that ends at 28 days - or 4 weeks); she's an infant/baby. She has more needs than "habits". In fact, I can't think of a single 'habit' a two month old baby can have. And I'm thinking hard. Maybe she has the gross motor skills to successfully suck her fists now, but it isn't a habit yet. She will develop habits. But not right now.
If she cries, she has a need. Her basic needs are food, warmth/comfort (e.g. from dirty nappies), exposure to stimuli (e.g. language), reassurance, and sleep.
The world is a harsh place for a baby. How well adjusted a person will be depends a lot on what you teach her about the world now. If you don't meet her basic needs, she will learn that the world is unsafe.
Whether you want to meet some of those needs is your choice. The way you frame certain behaviors ("sometimes she drinks very little then cry for hunger in an hour") makes it sound like she's doing something "wrong". Breastfeeding is part art, part knowledge. Maybe she didn't get enough milk and really is still hungry. Maybe she has gas and is crying because of that.
In many cultures past and present, certain needs are disregarded in favor of other behaviors, so you would be far from alone in choosing to ignore certain needs. But they are needs, not simply wants, at this point.
When can you spoil a baby? I think there is no exact age, but the many pediatricians say you can start "Ferberizing" a baby (teaching self-soothing to allow the baby to get to sleep on her own) at 7-8 months. This was confirmed in a reasonably sized Austrailian study.
I would imagine this is the earliest you can start to train a baby.
A case can be made for speech as an example of training a baby. Some babies can say their first word at 7 months (very unusual, but it happens.) Others are still only babbling at 8-9 months. As with everything, babies vary in their abilities, but within a range.