Ok my question is I know distant spell doubles the spells range but does it also apply to the branch offs like in chain lightening that have a range of 30'?

No.

Thank you. Wasn't sure and couldn't find a similar post about this.  

I'm finding several things that seem to worded in an ambiguous way in the spell description for Chain Lightning is worded:

1.  Can the initial target be either a creature or an object?
2.  The lightening doesn't jump to up to three other targets, if the original target makes the DEX save, correct?  (What if there is immunity to lightning damage? I assume that there would also be no lightning jumping to other targets)
3.  The damage is rolled just once, but the entire amount of damage is sustained by all the targets and is not divided among the targets, right?
4.  The up to 3 additional targets also make a DEX save and take full damage on a fail and 1/2 damage on a successful save, right?

bonus question 5.  It seems like it might be a pretty good damage spell, and might also be fun, right?