“Liberation is not fragile.”
If, right now, your state of liberation is determined by something as superficial as what you eat, or whether you are living as an ascetic in the middle of the forest or in the center of a city, or whether you are rich or poor, male or female (there are even some Jains who have declared that only males are capable of coming to their awakening), whether you are having sex or not having sex, then one’s so called “liberation” is fragile. Freedom is choicelesss. Whether you do nothing or do something, it is just like a lotus emanating it’s fragrance, not for any particular reason, but simply because it is one’s nature to do so. The problem that happens along the spiritual path is that often times one thinks that just by doing certain things mechanically, by following certain rules and regulations, that this in itself is going to lead to one’s enlightenment. And there have been people who have been practicing for almost their whole lives, and have remained just as unconscious and asleep as they have always been - in some cases even more so. Because once you start a practice, if you are attached to the outcome, then your practice is only going to be successful in re-enforcing your programming.
“I wonder how these methods take care of the karmic aspect”
That depends on what you mean by “karma”. The problem with “karma” is that all too often it has been interpreted according to a belief system. The Buddhists have their own idea as to the workings of karma, the Hindus have their own ideas as to the workings of karma, the Jains have their own ideas as to the workings of karma - and in some cases their interpretations are absolutely opposite to one another. Some yogis are strict fatalists - whatsoever you do, you cannot change your karma - you have to live it out regardless of your circumstances. Others have been far more flexible in their attitude - if you are suffering, unless you come to understand the root causes of suffering which have been created by your own hands - then not even infinite mechanical training will be of any help.
What is important is not whether something is “true” or not, but whether it is capable of assisting you towards your liberation. For this - there are countless skillful means. The word “karma” simply means action. If you think the quality of your actions are determined by the actions themselves - then you should consider that there is no humbleness in bowing down, nor is there silence in sitting still, nor is there compassion in giving money to the poor. It is one’s inner state of awareness which determine the quality of one’s actions. If you understand this - then it is possible to make an enormous leap forward in one’s practice. Because even something like an asana, it’s impact upon your system has less to do with the posture itself, and more to do with one’s awareness. The same is the case in sitting meditation - you may be sitting absolutely still, without even a single ripple of movement with the spine erect, your head balanced in the center, your tongue touching the upper palate, and having taken care of all of the common formalities - but inwardly you are a mess, there is a great storm raving. And there are those who - understanding the spirit of meditation, can be involved in what appears to be a great storm, but inwardly they are absolutely silent.
Actions have no quality in themselves. The reality is that you can eat meat - and without it leaving any “negative” trace on your karma if you do it with the right mindfulness. You can have sex, and if you are in a meditative consciousness, your lust does not become a barrier -on the contrary it contains enormous potential energy which can be transformed. And this kind of approach of not repressing the senses is the approach of tantra. Everything is to be seen, understood, and integrated - nothing is to be rejected or repressed. It does not mean senseless intoxication, it simply means involvement but with awareness. Rather than repressing the mind, you can confront the situation directly. If, for example, you have a fear of death - you can go live in a graveyard, surround yourself with as many scenes of death as possible. There is one very well known sadhana in the tantric sciences, sava sadhana, which has been precisely for that purpose. The yogi sits on a corpse during his meditation. And just from that suggestion - all kinds of ideas related to death are triggered in his unconscious. And with this direct and straightforward approach, one can confront the reality of death directly. This is a very different approach. For the Buddhists - they will instead simply contemplate about rotting corpses through their imagination. And whether it is just your imagination, or whether you are confronting the matter in a more direct manner, all of those methods work perfectly well as long as there is a certain stream of awareness which is flowing throughout. The moment one becomes involved in any practice out of unconsciousness - there lies the danger.
So, it may be useful for you to set aside all of your fixed ideas as to what is the “proper” or “improper” method for transformation, there is no such thing. As far as the paths are concerned, there are millions of different strategies towards one’s liberation, no single approach is absolute.