Will a person's repentance be accepted if he stops talking to another Muslim?

Q: If a person is not talking to another Muslim then their repentence is not accepted. If this is true and a Muslim isn't speaking to another because he insulted him or a loved one and hence isn't talking, and repents to Allah for his past sins, his repentence and sins won't be forgiven by Allah because he isn't speaking to a Muslim?

If that is the case then how can one get their sins forgiven. Everyone has atleast someone they don't speak to because of something they said or did.

What if the Muslim he isn't talking to lives far away and he repents to Allah for  sins, will his repentence not be valid?

Is it true that Allah won't accept someone's repentence because they aren't speaking to another Muslim?

Performing salaah while having the urge to relieve oneself

Q:

1. Could you please tell me what to do when I come across a situation where I have to relieve myself (in the bathroom) at that time of salaah (especially fajr and magrib). Should I control myself and make wudhu and go to the masjid for salah or should I go to the bathroom and then go to the masjid and read salah without jamat?

2. What are the situations in which delaying salah is permissible, because when it comes to salah and I have a situation like that, then I get tensed and get a headache and my heart starts beating fast. 

Making up for salaahs missed while one was an apostate

Q:

1. As a youth, someone made an oath to not do something and they did it, they then fasted 3 days to expiate the oath (as they were unable to do anything else). Later that person apostatised from Islam but came back to the Deen. Do they have to redo the expiation for the oath broken? No oath was made since that time. 

2. Also, in terms of salah missed, are salahs missed over years must be made up by someone who Apostatised but later came back to the Deen?