I haven't read the comic either---just summaries.
Anyways, as to why a mining ship crew (purely IMHO):
1. Rogue/disgruntled military officer is over-done. An 'everyman' is more relatable and atypical.
2. Military ships wouldn't have giant hanging mine-drills, for the orbital-skydiving sequence, fist-fight-on-the-platform sequence, and drilling-out-the-core sequence.