There are plenty of ways to emphasize something (see the tip on headers here), but you really don’t need to use multiple at a time.
Larger and thinner? Cool.
All caps? Fine.
Bold and underlined? No. No no no no.
Italics and red? Please, stop.
Large and underlined and italic? This should be illegal.
Change something enough so it looks different, not so much that it hurts people’s eyes.