First off I might be wrong since I’m not scientist if someone has more accurate answer be happy to chime in.
To the first question
Simple answer: No
For more complicated answer I’d recommend watching this video: https://www.youtube.com/watch?v=IVsWTkD2M6Q Although he uses many times larger magnets than is going inside our bodies and not human blood.
I would not recommend installing xG3 to your fingers since it’s bigger than titan. Some that have hand on the larger side that have managed to do that well but at least for me it wasn’t an option. Maybe hand blade would be better or P -0 (opposite site of hand than P0, there’s some examples here on the forum) I have my xG3 V2 in a blade of my hand and have been happy. Titan is more finger friendly and have been happy with my titan for a half a year now in the ring finger littlebit on the lower on the passing and outside side on the hand. If you have slender and/or small hands and install xG3 in one of your finger I’d think that it would restrict the movement as well.