Obligations towards the Neighbor
Question :

What is our obligation towards the neighbor?

Answer :

It is prohibited to harm the neighbors, and it is highly recommended to be kind with the neighbors and to deal with them in a good way.

Transgression against Believers
Question : Are there any cases/situations in which Islam permits suicide?
Answer : Islam does not allow suicide in any way or form.
Abandonment
Question :

Me and my friend had a fight and we are not talking to each other for the past two years. Someone told me that this is prohibited. Is that true?

Answer :

Based on compulsory precaution, one should not desert a believer for more than three days, even if the latter was wrongful to him. It is sufficient to satisfy this obligation by greeting him (e.g. saying 'salam alaykum'). If the other party insisted on the abandonment, he will become the deserter.
This prohibition has three exceptions:
First: if the desertion was to forbid the wrong.
Second: if the desertion would lead to a benefit that the Sharia recommends, like - for example - if desertion leads to paying attention towards a truth that could remain hidden without such desertion, or similar cases.
Third: if the reestablishing the relationship would lead to demeaning oneself. One should be careful in not confusing arrogance and anger with self-demeaning.