Feivel, the “going up three times after shemona esrey” is a nonsensical minhag nashim. Azi, agreed that some minhagim have no mekor. I haven’t found a mekor for pointing with the pinky or kissing it. I once asked a rav, who told me that any minhag that we can’t passul as a minhag shtus or a minhag ra has the status of minhag yisroel kodesh. In this case (pointing with the index finger), the Sefer Chassidim and Rav Chaim Palagi ZT”L bring it down, taking it out of “questionable minhag” status. The Siddur Vilna also quotes some midrashim in Shir Hashirim which translate “Diglo alai ahava” as godlo alaei ahava, that when you point to the name of Hashem with the index (the finger next to the agudol, or thumb) Hashem gets nachas.
The pinky has no mekor as far as I see except as a distortion of pointing with the index finger. It’s meant to show respect for the Torah, however, and as such it’s not worth making a fuss about. What is clear in halacha is:
1. Seeing the writing, which brings all sorts of holy influence on a person.
2. Saying the passuk of Vezos Hatorah.
The “al pi Hashem beyad Moshe” is also very questionable, as it’s half a passuk with Hashem’s name in it. Some leave it out or say the full passuk ( Al pi Hashem yachanu ve’al pi Hashem yisa’u, es mishmeres Hashem yishmoru al pi Hashem beyad Moshe)