After playing this game through I've found that some characters can be easier than others to get influence with than others. For example:
Those who you gain most of the needed influence just from talking:
Kreia, Visas, Handmaiden, Disciple, T3-M4, Mira & GO-TO
Those who you gain most of the needed influence from walking around w/you:
Bao-Dur, Atton, Mandalore, HK-47
The others were easy, except for Bao-Dur, he was more difficult. But I haven't been able to get ANY influence w/Mandalore or HK-47 AT ALL!
Please Help!