Salamun Alaikum,
The Quran in Arabic is simply a 'message'.
Wisdom (hikmah) from the Quran has no language. It is universal independent of language. The Quran's 'message' is futile if correct wisdom can not be extracted from it.
It is not as if the Arabs do not understand the Arabic of the Quran. Many do ‘straight off the bat’. The problem is that they attempt to understand the Quran from the
lens of the 'Hadith' corpus and reconcile the two for which the Quran gives no authority. So their approach is
'compromised'. Similarly, it was not that some 4th century Christians could not understand the early Biblical scriptures in Greek or Latin, it was that they attempted to understand the Bible through later 'Biblical doctrine' such as the Trinity. That compromised their understanding.
It is not only the language of the message which is important, but also acknowledging the approach that the scriptures want you to take when interpreting them. This is fundamental.
It is the 'message' and its wisdom which is protected. The language is only a vehicle.
Therefore, in response to your questions:
(1) Please do your best to try to learn the language if you can.
There is nothing better than accessing the Quran directly for yourself. However, be aware that the Quranic Arabic is not spoken today. It is a classical dialect / language and the vernacular of the Quraish who were a specific people of a specific time.
However, I would strongly recommend 'Fus'ha' or MSA (Modern Standard Arabic) (type spoken by newscasters, found in academia, journalism etc) which will assist you tremendously in understanding the Quran to a considerable degree. But if you can't, I would simply try to understand the Quran the best you can through the renditions of different translators and a word-word tool such as the two below.
http://www.islamawakened.com/quran/ http://corpus.quran.com/wordbyword.jsp (2) The message of the Quran is in tact as we have the original Arabic. What we have are different 'takes' of the verses from translators when they attempt to render the Arabic to a different language. Some renditions are very questionable. But the ones you mention such as
Yusuf Ali and Pickthall are very good. However, no translation is perfect of course and sometimes translators attempt to reconcile their rendition with extant theology.
Although, I study the Arabic directly, but if I were to pick an English rendition I personally like, it would be Pickthalls' rendition. I think it is a master-class in the way it makes use of a certain style of English to capture the Arabic. But that does not mean that I agree with all the verse renditions, for example, please see the following article.
http://quransmessage.com/articles/did%20solomon%20really%20slaughter%20his%20horses%20FM3.htm However, I would still highly recommend the translation as it attempts to stay very close to the original Arabic as a 'literal' translation. The verse rendition above is in my view an exception / anomaly.
When I listen to the Quran, it has a very majestic, powerful tone, almost mesmerising incantation to it.
As far as the Ahadith, the Quran in Arabic itself denies the
'authority' of any other source. So whether one is Arabic speaking or not, this is a question of whether one wants to accept what the Quran is saying or reject it.
This is not a question of language. This is a question of ‘submission’ to the Quran’s testimony.
I hope that helps, God willing.
Joseph.