Muslims use the multiple versions of the bible and the argument that it was compiled by human committees to bolster their claim that Judaism and Christianity have been ‘corrupted’. Young Muslims are taught this first at a very young age.
Anyone attempting to convert a Muslim will find this point and their revulsion to the idea of God having a Son as the most difficult to overcome.
As one who has also evidenced unbelief in the Bible and scorn of the God of it, your input is not surprising. However, as regards the efficacy of objections to Bible versions, what negates their argument is that absolutely none of the Biblical mss, including those which antedate the Qur'an, concur with the Islamic contradictions of it.
In addition, the theory that the Bible was changed, so as to make Jesus the Son of God who died for our sins and rose again, would not simply require a few changes but almost a complete rewritting of the NT and substantial changes to the old.
Moreover, if the Catholic church was responsible for these then it was very neglectful when and if it had such power to make even small and easy changes that would give clear support for many of its teachings (calling elders "priests," praying to the departed, etc.)