I believe they existed but I don't believe in their divine-nature. I think they were normal people but good ones.
Muslims also believe that messengers and prophets are not divine. Where did you get an idea that muslims think they were divine? I think you confused Islam with christianity.
Not only. Another problem is the religious people are not open-minded and refuse any other person who doesn't have a religion though he/she may be a good person.
Allah SWT through Islam tells us to be kind and just to everyone. And Allah SWT has provided Qur'an and prophet Muhammad SAW as guidance for mankind.
What do you mean by "refuse any other person who doesn't have a religion though he/she may be a good person"?
Wrong. I never thought life is a paradise. Life is not easy. As previously said life to me is a test which should be overcomes successfully in order not to fail.
This life is a test for eveyone, and the measure of success is whether we will attain paradise after death.
And the only way to attain paradise is to obey Allah's commands.
They could be man-made just like Islamic religion. I don't think anything/anyone can prove if Q'uran is the truth...
Please visit countless threads already made in this forums alone (mostly in Clarifications about Islam) that proved Qur'an is the truth.
It is then up to you to accept or reject it.
QS. 6:46
Say (to the disbelievers): "Tell me, if Allah took away your hearing and your sight, and sealed up your hearts, who is there - an ilah (a god) other than Allah who could restore them to you?" See how variously We explain the Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.), yet they turn aside.
From what you have posted so far, I can only assume that you have very little knowledge about Islam (although you
MAY think you are very knowledgeable) and very much influenced by western ideas about Islam and religion.