Black Widow, along with half of Manhattan, receives viral spider powers in the animated series Marvel's Spider Man - Spider Island Part 2.
We don't see her use spidey-sense, but she slings web, crawls on walls, leaps high into the air and punches like a champion,
In the Ultimate Marvel universe/line of comics, the original (Natasha Romanova) Black Widow dies, and a couple of other characters take up the name while working for SHIELD.
One of the other characters who takes the name Black Widow is the Ultimate version of Spider-Woman, a female clone of Peter Parker who most definitely has spider powers.
As far as I'm aware Black Widow has never had physical Spider-Man-like powers. However, in Amazing Spider-Man Vol. 1 Issue 86 Black Widow upgrades her costume and equipment. As part of that process she upgrades her Widow's Line: an imitation of Spider-Man's web shooters.
Click image to enlarge.
Her suits have also been shown to be able to cling to walls ...
Thanos' mission was to save the universe by halving its living population. Once he did that he had no need for the Infinity Stones and they could "only serve as a temptation".
Thanos: The universe required correction. After that, the Stones served no purpose, beyond temptation.
He also did it so no one could undo what he did. He ...
Beck mentions his name during the speech:
Quentin Beck: To Guterman; the story you created of a soldier from another Earth named Quentin fighting space monsters in Europe is totally ridiculous, and apparently exactly the kind of thing people believe right now!
Spider-Man: Far From Home
And whilst I'm pretty sure your title is written ...
In short, no. In long, they are both. Frenemies or "The enemy of my enemy is my friend" by Sun Tzu explains their relationship quite well. It has been a complicated relationship between the two, over the years. Adam is Life's Champion and Thanos is the Death's champion (Vol. 1, No. 11, 1976, Comic 02153 - Warlock - The Strange Death of Adam Warlock) .
Basically, Wanda didn't hold Thanos back. He let her think he did for an easier win.
There are main 2 factors in play here. The gauntlets power and Thanos's pride. Wanda's power is a tertiary factor. Spoilers ahead!
Secondly, Thanos's downfalls is pride. Thanos is a master tactician (or overly cautious) and knew he could reverse time and take the stone ...
The comics do not say specifically how the soul stone ended up in the High Evolutionary's possession. It does mention some facts and lets you guess how it got their though.
In Warlock Chronicles #1 the soul gem explained it's history. Darklore and Meer'lyn revealed it's sentience when Adam Warlock was knocked out. The soul gem said:
I am one of six ...