**Would like to ask if my method of meditation(Mahasi method rising-falling) is correct.** 

If you try to validate this against the teaching of the Buddha as per the Pali Canon, this is not a valid or correct technique. More on this see [this answer][1] and other referenced material. 

Suttas which cover insight meditation are:

 - Maha-satipatthana Sutta
 - Anapanasati Sutta

They do not have any reference to either noting nor the rising and falling of the abdomen. It is later innovation like this which lead to the decline of the Dhamma. For more information see [this answer][2].

**When some feeling arise in me, most of the time, i can noting the feeling was somewhere in the body( example: scare feeling near my abdomen/ back of my body).**

Getting sensitive to sensations is a good thing. You have to see how this lead to unwholesome states.

> (1) the latent tendency to lust reinforced by being attached to pleasant feelings;

> (2) the latent tendency to aversion reinforced by rejecting painful feelings;

> (3) the latent tendency to ignorance reinforced by ignoring neutral feelings.

[Pahāna Sutta][3]

Also how it relates to causality

> As such, bhikshus, the instructed noble disciple closely and wisely attends to dependent arising itself, thus:

> Imasmiṁ sati, idaṁ hoti; „When this is, that is;

> imass’uppādā, idam uppajjati. with the arising of this, that arises.

> Imasmiṁ asati idaṁ na hoti; When this is not, that is not;

> imassa nirodhā idaṁ nirujjhati. with the ending of this, that ends.‟

> Bhikshus, dependent on pleasant contact, a pleasant feeling arises. With the ending of the pleasant contact, the pleasant feeling that arose in dependent on that pleasant contact, ceases, is stilled.

> Bhikshus, dependent on painful contact, a painful feeling arises. With the ending of the painful contact, the painful feeling that arose in dependent on that painful contact, ceases, is stilled.

> Bhikshus, dependent on neutral contact, a neutral feeling arises. With the ending of the neutral contact, the neutral feeling that arose in dependent on that neutral contact, ceases, is stilled.

The whole scene shere is unsatisfactory. The impermanence and non self nature contributes to this also.

> regarding pleasant feeling, what is pleasant, what is painful,?

> regarding painful feeling, what is painful, what is pleasant?

> regarding neutral feeling, what is pleasant, what is painful,?

[Cūla Vedalla Sutta][4]


**I would like to know when i noting the feeling part inside/outside the body, is this the right way? i did not do it purposely but i can just feel it when i concentrate'**

This is also a good sign. Totality of insight include:

 - internal (ajjhatta)
 - external (bahiddhā)

So you are experiencing this. For more on this see [this answer][5].


  [1]: https://buddhism.stackexchange.com/a/19051/295
  [2]: https://buddhism.stackexchange.com/a/21118/295
  [3]: http://dharmafarer.org/wordpress/wp-content/uploads/2010/02/31.1-Pahana-S-s36.3-piya.pdf
  [4]: http://dharmafarer.org/wordpress/wp-content/uploads/2013/04/40a.9-Culavedalla-S-m44-piya.pdf
  [5]: https://buddhism.stackexchange.com/a/21175/295