Is 2kg static cross-load dangerous for a carbon frame? The bicycle is a carbon fiber cross-country machine. It is from a local manufacturer, not a well known one.
Compared to other CF bikes but for more aggressive riding, when I knock on the tubes it feels that the wall thickness is half of the others! Nevertheless, it handles it's purpose well.
I am contemplating is it safe to add a triangle bag with a multitool, tube, oil, rag. &lt;TODO: I have the bag, just equip it and weigh it&gt; &lt;TODO: add picture&gt; Intended application: cross country with rock gardens and drops below one meter. My worry is that the bag is going to load the top tube radially. And the end strap is at the middle of the tube where it's certainly weakest.
Opinion, but a frame bag won't cause any problem for a normal bike frame.  If it were an ultralight hillclimbing bike with no paint or something specialist, then I'd worry.
If you're concerned about fretting of straps on the clear coat, get some of those clear frame-protection stickers and apply to the frame under any retention straps for your bag.  Also cinch velcro straps down firmly.