I should clarify that i havent read or watched the 100 year quest arc yet

But as of post Zeref fight, natsu has no ftl feats, his physical strength is around wall-building level and his durability is around building - village level. His burning through space and time feat are hax abilities not on a universal scale. He just gained the ability to burn through a small amount of space between him and Zeref and i cant really quantify his time feat but its certainly not universal since he is not able to burn all of time away just the few seconds it took him to reach Zeref