The question is about touching the Torah scroll. The prohibitions against touching the scroll are both practical and Rabbinical. We do not touch the Torah scroll out of respect and reverence for G-d’s Word, of course. According to the Rabbinic rulings, one becomes ritually unclean from touching the scroll and the mitzvot of reading from it is negated. However, this is not written in G-d’s Torah. Indeed, I submit that reading from the Torah is a mitzvah whether or not one has a Torah pointer (Yad) , or anything else with which to touch the scroll.
Practical reasons include the fact that oil from skin can cause damage to the fragile parchment and in some cases can cause the ink to smear, thereby “defacing” the scroll in a manner of speaking, although unintentional on the part of the one touching it.
On the issue of wrapping oneself in the scroll, that must be left between the individual and G-d. I do not advocate for this practice , but HaShem knows the heart and the circumstance and will judge the individual who engages in such as act. I submit the tallit is for wrapping oneself in a prayerful posture, whether in joy or sadness and supplication.
I hope this helps.