To change these permanently you will need to unpack the mission and adjust them in the lobby screen, "Parameters" is located in the upper right side. For a SP/MP local host you should only need to adjust them when you first begin the mission at the top right of the lobby screen.

Day Length: 2 hours (real time)
Shorter Nights: Yes
Adapt to Player Count: Yes
Resource Mulitiplier: x50
Fatigue: Off
Passive Income: On
Ammo Bounties: On
Halo Jump Timer: None
Max Squad Size: 30
Max FOB's: 26

RESET MISSION / DELETE SAVE:
To restart your save you must use the parameter options and set "Wipe Savegame" and then set "Confirm: Wipe Savegame. Upon parameter accept it will erase all progress in the mission and start you fresh.

RHS Infantry:
Only available at the Chimera base via a Flag pole near spawn. This flag pole can be used to spawn RHS and APEX infantry and add/remove them from HC.

FOB:
Be sure you are far enough away from all capture points and base Chimera (~725m) or it will not allow you to build. IF YOUR FIRST FOB IS LOST/DESTROYED PRIOR TO SETUP, it is a 50/50 chance it will respawn. If it does not reappear at the FOB spawn location after a restart you will have to do a full save wipe through Parameters or go on without the units it provides.
*** HINT: Build one as a back up ASAP from the FOB Menu once you get the first one built, leave it at the main base.