Some potential answers:
1.) If you look under the Race Features on the first page of the sheet, it should say "Choice of Bonus At-Will Power or Heroic Effort (see Filters)". This indicates that you need to switch to the 'Filters' tab and select which racial power you want to take to the right of "Human Racial Choice:"; this will let you pick between the Essentials human racial, or the PHB one.
2) The utility power you want should be available in the drop-down of a cell in the Utility Powers section on the second page of the sheet. Note that the Level 2 utilities all have skill training prerequisites, so if you want to take single out, make sure there is an X in the 'TRND' column next to the Intimidate skill. The selection of this power might be being hindered by the answer to #1 above, as well.
What you said about Heroic Effort worked, I found it and it's all good.
However, I followed the steps you mentioned for Single Out, and it simply didn't work. It was probably just forgotten about. Intimidate is checked. as well.
Edit: Played around a bit with this Slayer build, and moved him up to level 5, which is supposed to give him Mighty Slayer. Instead it remains at Heroic Slayer. Again it seems like Class features are not being upgraded for Slayers at the very least.
Also, with Single Out it is available for fighters (since is a fighter utility), but not available when choosing for Slayers, but at least I know it's in the system for sure.