Mon coeur se bat ou mon coeur bat?

Question

why isn't it reflexive and other things that work like that.

and how does the le neuter pronoun thing work

Answer 1

1.  Definition of reflexive verbs:

"Reflexive verbs are verbs which are used with a reflexive pronoun in addition to the subject pronoun, because the subject is performing the action of the verb upon him/her/itself." *

The heart does not perform the action of the verb upon itself, so, "mon coeur bat" is the correct phrase.

battre = to beat (battre is an irregular "re" verb)

se battre contre = to fight against

combattre = to fight/combat

2.  "Le" is used as a neuter object pronoun in certain constructions, but it is formal and mostly used in written French and it is optional.

There are quite a few situations where it is used so I am including a link which explains its usage very clearly:

http://french.about.com/library/weekly/b...

Answer 2

Mon coeur bat.

Do not understand your second question.  

Answer 3

se battre is to fight.

battre is to beat