which view should a muslim living in country other than saudi do, follow majority for ramadhan orfollow saudi for their timing?-

asalam alaykum

which view should a muslim living in country other than saudi do, follow majority for ramadhan orfollow saudi for their timing?- is saudi like the main decision maker for ramadhan and islamic month for the world? why do so many people believe this, did the prophet (saw) make saudi as the criteria or where we live?

an example is in uk where majority started their fast on sunday morning, while arabs and bengalis on saturday morning. they keep claming that we are supposed to follow the saudi for their timing, if thats the case why dont they just read salah according to their timing not in uk, why not read maghrib when it is asr for us?

based in quran

"...So whoever of you sights (the crescent on the first night of)
 the month (of Ramadân), he must observe Saum (fasts) that month..."

[Holy Quran 2:185]

i have read in hadith that
Ibn Umar (ra) reported that Allah's Messenger (pbuh) made a mention
of Ramadan and he with the gesture of his hand said: “The month is
thus and thus. (He then withdrew his thumb at the third time). He
then said: Fast when you see it, and break your fast when you see it,
and if the weather is cloudy calculate it (the months of Sha'ban and Shawwal)
as thirty days.”

and

Kuraib (ra) reported that Umm Fadl (ra), daughter of Harith,
 sent him (Fadl, i.e. her son) to Mu'awiya (ra) in Syria. I (Fadl)
arrived in Syria, and did the needful for her. It was there in Syria
 that the month of Ramadan commenced. I saw the new moon (of Ramadan)
on Friday. I then came back to Medina at the end of the month. Abdullah b.
 'Abbas (ra) asked me (about the new moon of Ramadan) and said: When did you
see it? I said.: We saw it on the night of Friday. He said: (Did) you see it
 yourself?-I said: Yes, and the people also saw it and they observed fast
and Mu'awiya also observed fast, whereupon he said: But we saw it on Saturday
night. So we would continue to observe fast till we complete thirty (fasts)
 or we see it (the new moon of Shawwal). I said: Is the sighting of the moon
 by Mu'awiya not valid for you? He said: No; this is how the Messenger of
 Allah (pbuh) has commanded us.

if thats case, why is there so much curuption regarding this? why do they not follow
the hadith of bukhari and muslim?

and also, do non muslims go to heaven due to this quote

Those who believe (in the Qur'an), and those who follow the Jewish
(scriptures), and the Christians and the Sabians,- any who believe
 in Allah and the Last Day, and work righteousness, shall have their
 reward with their Lord; on them shall be no fear, nor shall they grieve.