Question: Is there a t'shuvah which addresses the question of permissibility of reading Torah from a printed sheet in order to ensure correct pronunciation, as opposed to reading Torah with multiple mispronunciations and few corrections?
If you had to make a choice between the two extremes of someone publicly reading from the Sefer Torah with an untold number of pronunciation errors (not to mention trope) as opposed to the same individual reading the Torah reading perfectly from a printed page in front of the Sefer Torah, what would be your "final say" and why
Answer: There is no teshuvah in the Conservative movement that addresses the question of reading Torah (with blessings) from a printed page. The traditional position, according to halakha, is that the when the Torah is read in public with berakhot, it must be read from a kosher Torah scroll.
There are certainly people who read Torah who make mistakes and need to be corrected. Nevertheless, I do insist that it is not only the correct halakhic response but it is also a greater honor for Torah and respect for God's voice in our tradition to read from the Sefer Torah than from a printed book. You are suggesting that there are only two possible choices - reading well from the Humash or reading poorly from the Sefer Torah. I suggest that there are other options. Torah reader can improve their skills, or failing that, they can be given one very short aliyah and more competent readers can read the rest.
I should also note that it is the job of the gabbai’im to judge when it is appropriate to correct the Torah reader. Corrections shouted from the congregation are unnecessary and distracting, both for the reader and for the other congregants.