riddle - Name that Sandwich

Light, soft and healthy is me
mirrors are all over these
if finding gold is rather dismal
I sit next to the one in Pepto-Bismol

Different letters here is your goal
somewhere to go with an unfortunate hole
Equestrian researchers aren't quite right

take from the morning not from the night

Careful not to shoot from the hip
take a bow and get a grip
the vikings watch me in awe
I hate my bed I'll stay up more

These three up high are not the same
but their collective being will grant you fame

Answer

LEADERSHIP.

Light, soft and healthy is me
mirrors are all over these
if finding gold is rather dismal
I sit next to the one in Pepto-Bismol

Mirror suggests reversal. The opposites of light, soft, and healthy are heavy, hard, and unhealthy. What is heavy, hard, unhealthy, and can be used to find gold? Ancient alchemists wanted to turn LEAD into gold, which is actually possible (though unfeasible) by nuclear transmutation. LEAD is heavy and unhealthy, and post-transition it is classified as a hard metal. It's also adjacent in the period table to bismuth, which is contained in Pepto-Bismol.

Different letters here is your goal
somewhere to go with an unfortunate hole

Equestrian researchers aren't quite right
take from the morning not from the night

The answer to the second verse is two different letters taken from the word "here". The only possibilities are H and R, E and R, or H and E. If you have an unfortunate hole, you go to the emergency room. Take letters from the morning (the start) not the night (the end) of Emergency Room and Equestrian Researchers to get ER.

Careful not to shoot from the hip
take a bow and get a grip
the vikings watch me in awe
I hate my bed I'll stay up more

"S[hoot from the] hip" and Vikings, famous for going around in longships, suggest the word SHIP. Cannons on SHIPs must not be fired from the hip! A SHIP has a "bow" meaning front, and you can "get a grip" on the wheel. And a SHIP hates the seabed, preferring to stay well above it. (Also if you're on one you might sleep in a hammock, which is higher up than a bed.)

These three up high are not the same
but their collective being will grant you fame

We have LEAD, ER, and SHIP. Put them together to get LEADERSHIP. Hurray!