See Rav Shmuel Halevi Wosner(Vozner) in his Shevet Halevi who says definitively that it is a mitzvah.
See as well Rav Avraham Abraham in his Nishmas Avraham(Vol. 3(Even Haezer), Siman 80, Os 1) who writes that it is a mitzvah to give bone marrow for a bone marrow transplant, he quotes his response with Rav Shlomo Zalman Auerbach who agrees. I assume the same ...
R Abraham S. Abraham, the author of the Nishmat Avraham compendium of medical halacha, writes (vol 2, p. 346)
Rav [Shlomo Zalman] Auerbach wrote to me that he also permits donating
blood to the blood bank in Israel, for the donor performs a mitzvah
of saving a Jewish life, even if does so only for the money.
See also this detailed analysis by R Aryeh ...
HaRav Eliezer Waldenberg zt"l has a famous piece in his Tzitz Eliezer (vol 16, siman 23). He notes that it is definitely a mitzvah but one is not obligated (and would in fact be forbidden, if it would cause a decline in health of the donor).
מי שחפץ ברצון עצמו לתרום מדמו ומרגיש שלא יוזק מזה, מדת חסידות יש בזה, ואשרי חלקו מי שיוכל לעמוד בזה
In Egypt a case was discussed about donations from unsavory sources. In the end Moreinu Shim'on ruled that they could accept donations even for sifrei torot as long as you remove potential stumbling blocks from the donations, such as not allowing names to be inscribed on objects that may remind others of their sins.
"R. Raphael Aaron ben Shimon, Nehar ...
R Shimon Taub in The laws of tzedakah and maaser addresses your first question
If a Jew who deliberately transgresses major mitzvot (e.g., Shabbos)
wants to give tzedakah to poor people, one may accept his donation.
It is questionable if tzedakah may be accepted from such a Jew for a
shul but it has become a custom to do so for a shul or yeshiva.
Based on ...