The following is my understanding of the main thrust of early Buddhism.
If we start from the “three signs”, I read them as saying that all samskaras are impermanent and troublesome whereas all Dharmas are non-self. The meaning here is that self, (i.e. samskaras), is the problem. When one no longer has faith in the samskaras (mental confections) that constitute self, Dharma appears. The aim of Buddhism is to invite us us to abandon conceit and self-centredness.
Meditation is not so much a means to achieve this as something that people who have achieved it are likely to do naturally. Similarly, the eightfold path describes an outcome, not a means. Buddha did not become enlightened by following the eightfold path. He found the eightfold path by getting enlightened and that enlightenment consisted substantially of realising that all his previous efforts at self-enhancement were counter-productive.
If we then look at the Satipatthana Sutta we see that the culmination of the sutta - the result - is the eightfold path together with the seven factors, and the other key teachings. The Sutta describes the practice of a person who has mindfulness already established. It is not a recipe for developing mindfulness and mindfulness is not a state of here and now awareness particularly. A person with mindfulness who then practises awareness of physical (part one of the sutta) and mental (parts two and three) processes arrives at the Buddhist teachings (part four).
So what is mindfulness? Mindfulness is to keep in mind what has been taught by all the Buddhas back in time, which is the giving up of self. So meditation is what happens when a person sets aside the samskaras that constitute self, namely, greed, hatred and delusion.
Buddhism, therefore, is more an invitation than a method. It says, set aside selfishness and enjoy a different perspective. It also says that if you do so and then study life in detail, you are bound to arrive at the same conclusions as Buddha did. In this way one can, if one wishes, test the truth of Buddha’s observations for oneself.
However, it is not essential to do so: one can simply take refuge in the fact that the Buddha has already done this work and announced the Dharma and that may be enough. Taking refuge and diminishing self-importance is all that is needed.
For the ordinary Buddhist, therefore, the religion consists on revering the objects of refuge, diminishing the self and ardently and continually renewing one's act of taking refuge.
If one additionally wants to experientially reestablish the validity of the four noble truths, thirty-seven key teachings and so on, then fine, but don't think that by doing so one is raising oneself to a higher level or one will set off the whole self-centred conceit thing all over again. One will have, as another sutra says, got hold of the snake at the wrong end and if you do that it will bite you.