To 1: Yes. I can reproduce this issue anywhere where the embedded browser is used. This includes any browser widget in any project, the slate test app in the github repo (test suite 1 tab), your launcher (unreal engine/community tab), and the frag center in unreal tournament (which, by the way, is also blurry).
To 2, 3, 4: Well I’m not sure. Open anything that contains an embedded browser and scroll a page (it feels laggy) or open testufo.com (it shows running at 24 fps). I’m not aware of any settings that could be responsible for this.