As others have pointed out, shari is not that natural-looking on most deciduous bonsai. But let's not get ahead of ourselves...
When assessing any bonsai, do not start at the top and work your way down. Start at the bottom and work your way up. You have no surface roots or trunk flair at the soil line. You have a couple of bad roots emerging from the trunk above the soil. You have a lower trunk with no taper and no character, and it moves into an old die-back scar that is causing reverse taper.
These are the bigger issues with this tree that will take time and technique to fix (but they are certainly fixable).
For an elm at this time of year, the tree looks extremely weak. Have you inspected the roots? Given my comments above, my plan of action with this tree would be to get it out of the bonsai pot, check the roots, repot it into a larger container, and let it grow freely until next spring. Then in late spring, early summer I would consider a ground layer with an angled girdle to give the trunk basal flair and improve the surface roots. Once the air-layer is separated and established, I would wire my apex and evaluate whether I wanted to remove all other branches. Once the new branches bud and I can wire them, I would start to develop the final structure of the tree.
At that point, I would start to worry about the deadwood
I am not trying to make fun with your tree - it could turn into a really cool bonsai. But you have to learn to address the big issues first. Otherwise you will spend years hollowing deadwood, wiring branches, etc... and then five years from now realize - woops I guess I have to do a ground layer and remove all the branches I just spent five years building. Don't start building an ice cream sundae with the cherry