Can someone clarify to me how Jump Packs work? Do they modify your base speed only or do they modify the entire movement capability of a Marine?

I see it as all, since if you change the base movement it going to affect all the other types. So if AG bonus is a four if would be 8, 16, 24, 48 with a jump pack. If your using the flyer 12 it would be 12, 24, 36, 72.

I see the AM Wings of Angels only giving +20 to whatever move type being used so if charging with the above 44, or running 68 . Although I am not sure how others rule this or how FFG intended.

Hm I am playing an Assault Marine and in our group it doubles all the movement rates.

Jump packs double the marines normal movement. Also allows the marine to ignore any obstacles or terrain in his path (unless its a barrier in a hallway, kinda hard to squeeze through that). So agi bonus 5 would be a 12, 24, 36, 72 move rate with a jump pack (agi 5 +1 hulking = 6, 12, 24, 48 doubled). If using the jump pack in flying mode the character gains Flying 12. Flying with an effective ag bonus of 12 (no other modifiers such as size or talents etc.)